I've been in the same boat as many, trying to decide which to device to stick with or switch to. I actually started with a launch 6+ but after about 3 months started to grow a bit tired of transporting the size and dealing with the lack of portability options (re: one handed operation, jacket pockets). I suppose the honeymoon giant phone concept started to wear off on me. So, when Apple launched the factory unlocked devices, I decided to pick up an iPhone 6 to see how well I faired with it. After switching between iPhone types in excess of probably over 15 times

mad:

) - I finally settled on the iPhone 6.
It boils down to a few concepts:
1. Do you VALUE the ability to one hand operations? I do, BIG TIME. Quickly responding to a text or something as simple as leaning against a wall and checking my news app while having the ability to thumb through and read. These things are taken for granted once you switch to a larger device. Try being on a 6+ for 3 months, then gaining that ability once again to do one handed operations, its a miracle.
2. Portability. While the 6+ most certainly fit in my pockets, I still noticed it significantly more than my 6. I could put my 6 in my jacket pocket and forget about it. Not the case with the 6+. I also noticed that my hand got tired of holding it while reading news, macrumors or reddit while wrapping up my day laying in bed.
3. Screen size. Realize that the 6 is still bigger than the previous generations of iPhones by a LOT! Don't discount the fact the 6 still has a fantastically sized screen. The 6+ is MUCH bigger and should be used for the simple concept it has a bigger screen, re: media/web/reading, etc. I work from home. I'm always in front of my computer, so having these abilities to a larger degree are null to me. The 6's 4.7 screen is still bigger than previous iphones as I said, so, it works perfectly fine for me due to my arrangements.
4. Accessories. Cases for the 6+ are big, naturally. I noticed if I added any sort of case to the device that actually would protect it decently, added a lot of weight to it. Yeah, the weight in numbers is small, but regardless, it all adds up to the durations in how long you hold the device. Throwing on a Magpul field case to the 6+ (one of my favs) added a lot of weight and bulk (IMO) to a an already large iphone. I had to stick to very THIN cases like the Incipio NGP to keep the device thin and lighter weight.
And finally....
5. OCD. I actually am diagnosed with OCD (And take meds for it) but also have always well protected my electronics. So regardless, I noticed my OCD/Anxiety going crazy trying to keep the 6+ clean and well protected. Laugh all you want haha, but I know I'm not the only one here. My 6 is significantly easier to keep protected and cleaner, thus curbing my ocd/anxiety surrounding the device.
I hope this helps some people out. I realize some of my points wont ring for everyone, heck, we're talking very low weights as it is when it comes to these devices. But, I feel it all adds up and makes a difference. Overall, I'm very happy with the decision I made and am very happy with my 6. It and the 6+ are amazing devices. Just think about which you want more, a phone or a phablet and realize the cons that come with each.
Note: Battery wasn't a big deal to me as I work from home, so charging isn't an issue for me.