I've had an Imp (which my sister took when I offered her a knife from my collection) and have played alot with the U2. They both are small knives, well made, and have good blade steels/geometry. The Imp is dressy and the U2 more of a user.
I would go with the U2 It has a lanyard hole which, if you put a lanyard on it can make the small handle seem bigger. Which is a good thing with a small knife.
I hate tell you about another knife but take a look at Blade-tech's Mouse II. Same kinda price range that your looking in. It's a real beefy small knife. I have a Spyderco one and am very envyous my girlfriends Blade-tech one. Flat ground blade with a wide handle and lanyard hole.
Best of luck and let us know what you get and how you like it...