It's a question of personal preference
In an office environment, you don't want bulky thinks in your pants' front pockets (excluding the car keys, maybe).
Wearing a jacket is dependant upon the country you live/work in.
And putting the iphone in the back pocket is risky.
So up to now I preferred a belt-clip holster. It's easy to reach and of course having your personal name engraved on the front cover adds a nice touch...
But then when you put the seat belt on in your car - it's sometimes uncomfortable.
And when I'm at home or on a trip and wear say my Columbia convertible pants, the side pockets aren't always large enough to accommodate the belt clip, so it's difficult to insert/extract from the pocket, or it creates a very bulky pocket.
So in my opinion there are 2 alternatives: Either buy a case w/o a belt clip, or select one with a non-obstrusive belt clip.
This time I selected the case w/o a belt clip.
And this eBay guy has all the options, in addition to enabling you the selection of the external leather type and color, the internal microfiber color, the type of belt clip, the type of case closure (magnets, snaps...).
So basically this is really the realization of the old McDonalds' logo - have it your way...