i was in the same debate not long ago. I'm a fairly harduse guy. the 21 suits me fine. as others have posted the function is just amazing and the fit and finish is second to pretty much none. this is as close as you can get to commishining you own custom. and the warranty and customer service is great too. if you don't like tinkering with the pivot and making sure the centring is bang on after you use it or drop it and wonder why its still gritty after you oiled and cleaned it...the 21 is awesome. use and be happy. its made to be a fire and forget knife. all the best.