For a better review on this knife, check out this guy's review • Video
If you are looking for a knife with a D2 blade, this is a great value, seriously. I have another knife with this steel that cost almost twice as much. These knives have a great feel in your hand. The knife comes out of the package super sharp, which is nice since the last thing you want to do right away is sharpen D2 steel. I have both the 2.5 and the 3.5 models. Both knives were able to cut cleanly through paper, but were not sharp enough to shave with, although I did remove a fair amount of dead skin trying. The 2.5 is perfect for carrying in your pocket and the 3.5 will do well in a situation where carrying a bigger knife makes more sense. It really stands out hanging from your pocket.
The flip action took a little getting used to for me. It really helps if you have the knife oriented so the blade is pointing down, and let gravity help. Otherwise you might have to give it a little flick to get it to open all the way.
My only real beef with the knife is the blade lock. There isn't much room for your finger/thumb to engage it and it is slippery. So far I have only been able to safely close the knife with two hands, which is a real bummer. Also, the 3.5 is a little big, and I had it come off my pocket while sitting on a couple of occasions.