The only thing I can think of for differentiating between lots of very good multi-tools is to make sure that you've got the right sizes (not all of them have the same allen wrenches, for example). Then be sure it's not TOO tiny. If you have to tighten down the clamp on your hood so that it doesn't move and shut your brake on you (yeah, not fun), you want the allen wrench to be long enough to fit down in there to where the screw is. The 3-pronged ParkTools one works the best for stuff like that, but it's awkward to carry around. My Pedros multi tool is good enough to get me home, though it won't get it tightened all the way easily. If the bolts on your saddle clamp are similarly hard to get to, then that might also dictate which tool you get. Nothing like spontaneous saddle movement to make your ride unpleasant.