I'm glad I'm not the only one who doesn't mind the VZW version of the buttons. I'm having no problem with them at all. As others have said, I find I'm using Knock On mostly, but I was on a few calls yesterday and had no problem finding the appropriate volume key; I think the "hump" of the power button really helps differentiate vol up from vol down.
One note: I have a simple TPU case on the phone and the space for the rear keys is probably a couple mm wider than they keys all the way around, and I find this works very effectively to guide my finger where it needs to be.
I agree: a simple long press with the pad of my index finger works great for taking a screenshot. Very convenient.