Funny enough, opening the PM2 with my thumb is probably my least favorite way of opening it due to the chance of the compression lock pinching my hand. I far prefer doing the middle finger flick or depressing the lock mechanism and giving a small flick of my wrist to open it. If I am around any non-knife people though, I just use my thumb or two hands to open it so it's less intimidating. That being said, the PM2 isn't my first choice to bring if I know I'm going to be around NKP.
Current EDC rotation: Southard, Paramilitary 2, Sage 1, G10 DF2, Techno
On deck: Military, Caly 3.5, Air
Wish List: M4 Military, S90V PM2, Superblue Caly 3.5, G-10 Jester