For your consideration, I bought these three holsters and thought I would share my opinions on them:
#1: Seidio Spring-Clip holster (For phones with no case): http://www.seidioonline.com/apple-iphone-5-spring-clip-holster-black-p/hliph5as.htm
#2: Seidio Spring-Clip holster (For phones with case, known as "Surface" and also sold under the brand "Platinum" or "Pt" in Best Buy stores): http://www.seidioonline.com/apple-iphone-5-surface-case-holster-combo-black-p/bd2-hr3iph5-bk.htm
#3: Splash Alpha I Lambskin Leather holster (For phones with no case): http://www.splashproducts.com/product_p/spl-iph5-vllc.htm
Note: Splash also sells a Lambskin holster for phones with a case known as the Alpha II, but I did not purchase that one.
#1 Seidio Spring-Clip hoster no case
This is a no-frills holster that is great if you want to carry your iPhone with as little plastic as possible. It is light and has a good belt clip, but it rides a little high on the belt. It takes some coordination to move the spring-clip out of the way when opening it up and not drop your phone in the process. When putting the phone in, the spring-clip does rub against the top of the phone and out of the way before snapping into place. I did not get any scratches on my phone from this, however, because I do use a Best Skins Ever full-body skin on it.
One problem I noticed, though, was that I got two dents in the front skin from the corners of the holster, shown here:
Not a big deal, but if I were to keep this holster, I would probably sand those corners down to prevent repetitive damage to the screen protector. The skin I have on the phone does make it a very tight fit and a bit difficult to remove. If you get this holster, I would suggest not putting a skin on the sides to prevent sticking to the sides of the holster.
#2 Seidio Platinum Spring-Clip holster with case
This is the version they sell in Best Buy, which seems similar to the "Surface Combo" that Seidio sells on their website.
This is a really nice spring-clip holster and case combination. The case comes in two pieces that snap together firmly, has cutouts for the camera, buttons, and lightning/microphone/speaker holes. The case has a good matte texture and feels sturdy. The clip is a little beefier than #1 which means that it can lay sideways on a table for watching movies. The #1 holster cannot lay sideways on a table. But it also means that the whole holster sticks out a little more when it's on your belt, in addition to the additional thickness of the case and the clip sticking further out.
#3 Splash Alpha I Lambskin Leather holster
The reason I bought this one is because I had a similar holster for my Blackberry with the magnetic flap and I really liked it. Amazon reviewers said that this was the closest to that famous Blackberry holster for the iPhone 5, so I ordered it direct from Splash.
What I like about this holster is that it has a nice slim profile. Unlike the spring-clip holsters, there is no clip sticking out of the top that can snag on things. Its belt clip also has a slim profile meaning that it carries closer to your hip. Finally, this holster rides a little lower than #1 and #2 which I prefer. My only pet peeve is that the fit of the iPhone is not as snug as it could be, there is a little bit of wiggle room where it seems like they could have removed a bit of extra material and make it even thinner.
Now for some side-by-side shots:
And some hip shots in the same order #1, #2, #3:
You can tell from the location of the bottom of the case versus the top of my pocket that the Splash case definitely rides lower.
Finally, some backside shots so you can see the difference in profile of the 3 holsters:
Conclusion:
If you are shopping around for a holster and definitely want a spring clip holster, I would recommend #2, the spring-clip holster with a case. I'm not coordinated enough to open up the clip and not accidentally drop my iPhone while trying to pull it out, so I would be very nervous using #1. In addition, the clip on #2 is big enough to allow the phone to be put in backwards (face-out) and lay the whole thing sideways, which would be nice for watching movies or TV shows.
However, if you aren't set on a spring-clip, I highly recommend the Splash Alpha I Lambskin holster. As you can see from the last set of pictures, it does not protrude as much, has a secure magnetic flap, rides low on the belt, and because you pull the phone out from the sides straight out of the holster, less worry about dropping the phone as you take it out. It is also very compatible with the total-body skin because there is a little wiggle room in the holster. Of course, if you really want to have a case on your phone along with the holster, you could try out the Splash Alpha II, but I don't have any experience with that one.
Thanks for reading, and I hope this helps out anybody like me that was struggling to find a good belt holster for their iPhone 5.
#1: Seidio Spring-Clip holster (For phones with no case): http://www.seidioonline.com/apple-iphone-5-spring-clip-holster-black-p/hliph5as.htm
#2: Seidio Spring-Clip holster (For phones with case, known as "Surface" and also sold under the brand "Platinum" or "Pt" in Best Buy stores): http://www.seidioonline.com/apple-iphone-5-surface-case-holster-combo-black-p/bd2-hr3iph5-bk.htm
#3: Splash Alpha I Lambskin Leather holster (For phones with no case): http://www.splashproducts.com/product_p/spl-iph5-vllc.htm
Note: Splash also sells a Lambskin holster for phones with a case known as the Alpha II, but I did not purchase that one.
#1 Seidio Spring-Clip hoster no case



This is a no-frills holster that is great if you want to carry your iPhone with as little plastic as possible. It is light and has a good belt clip, but it rides a little high on the belt. It takes some coordination to move the spring-clip out of the way when opening it up and not drop your phone in the process. When putting the phone in, the spring-clip does rub against the top of the phone and out of the way before snapping into place. I did not get any scratches on my phone from this, however, because I do use a Best Skins Ever full-body skin on it.
One problem I noticed, though, was that I got two dents in the front skin from the corners of the holster, shown here:

Not a big deal, but if I were to keep this holster, I would probably sand those corners down to prevent repetitive damage to the screen protector. The skin I have on the phone does make it a very tight fit and a bit difficult to remove. If you get this holster, I would suggest not putting a skin on the sides to prevent sticking to the sides of the holster.
#2 Seidio Platinum Spring-Clip holster with case
This is the version they sell in Best Buy, which seems similar to the "Surface Combo" that Seidio sells on their website.



This is a really nice spring-clip holster and case combination. The case comes in two pieces that snap together firmly, has cutouts for the camera, buttons, and lightning/microphone/speaker holes. The case has a good matte texture and feels sturdy. The clip is a little beefier than #1 which means that it can lay sideways on a table for watching movies. The #1 holster cannot lay sideways on a table. But it also means that the whole holster sticks out a little more when it's on your belt, in addition to the additional thickness of the case and the clip sticking further out.
#3 Splash Alpha I Lambskin Leather holster
The reason I bought this one is because I had a similar holster for my Blackberry with the magnetic flap and I really liked it. Amazon reviewers said that this was the closest to that famous Blackberry holster for the iPhone 5, so I ordered it direct from Splash.



What I like about this holster is that it has a nice slim profile. Unlike the spring-clip holsters, there is no clip sticking out of the top that can snag on things. Its belt clip also has a slim profile meaning that it carries closer to your hip. Finally, this holster rides a little lower than #1 and #2 which I prefer. My only pet peeve is that the fit of the iPhone is not as snug as it could be, there is a little bit of wiggle room where it seems like they could have removed a bit of extra material and make it even thinner.
Now for some side-by-side shots:



And some hip shots in the same order #1, #2, #3:



You can tell from the location of the bottom of the case versus the top of my pocket that the Splash case definitely rides lower.
Finally, some backside shots so you can see the difference in profile of the 3 holsters:



Conclusion:
If you are shopping around for a holster and definitely want a spring clip holster, I would recommend #2, the spring-clip holster with a case. I'm not coordinated enough to open up the clip and not accidentally drop my iPhone while trying to pull it out, so I would be very nervous using #1. In addition, the clip on #2 is big enough to allow the phone to be put in backwards (face-out) and lay the whole thing sideways, which would be nice for watching movies or TV shows.
However, if you aren't set on a spring-clip, I highly recommend the Splash Alpha I Lambskin holster. As you can see from the last set of pictures, it does not protrude as much, has a secure magnetic flap, rides low on the belt, and because you pull the phone out from the sides straight out of the holster, less worry about dropping the phone as you take it out. It is also very compatible with the total-body skin because there is a little wiggle room in the holster. Of course, if you really want to have a case on your phone along with the holster, you could try out the Splash Alpha II, but I don't have any experience with that one.
Thanks for reading, and I hope this helps out anybody like me that was struggling to find a good belt holster for their iPhone 5.