I really like my 'itaste' stuff. The MVP2 would be my go-to PV when out of the house but for the issue of being to hard (for me) to press the fire button.
I had that complaint as well. I found that the most comfortable way to deal with it is to hold it in my hand like a cell phone and then press the button by the side of my thumb.....
works much nicer.
I also think the button loosens a bit with use.....
The battery life outweighs the button for me. I have a vv3 too, but it has been since retired as my backup since I use the mvp exclusively. I am loving the battery life and form factor.