O.K heres the deal, I've been in the knife using arena for a little while, at first I thought if a knife cost 60.00 dollars it should be the best knife on the planet, Which at the time I thought was a gerber knife that could be had at walmart. In 10 years I slowly found better and better brands, ie benchmade, microtech, ect.
Today I at only 24 years old will tell you that, the best folders I have found are chris reeve sebenzas, so Here is my opinions on the following:
20 Piece of crap, pick one up at the walmart for a scrapping tool to clean the propeller fins, or grass from the mower.
50 cut, pry, and dig. Lock up will suck and blade play will too. However, It should have a lock back mech that you feel comfortable with.
90 The knife will be a user. We have to be carefull the lock wont fail, because this knife will have to go through a few paces, if it is a liner lock, I would spine whack it because there are a lot of lock backs that are safer, keep your hands out of the way!! I am not responsible for your cuts!!
150 Regular user abuser knife, lock up should be pretty solid, not perfect, and there will be blade play.
250 This seems to yield a little better folder for an extra bill.
However if I'm going to spend 250.00 I'll jump a bill to the sebenza. For 350.00 retail, you will get a folder with NO blade play and NO lock play at all.
Plus a superior steel, Blade grind and fit. If your looking for a real high performance using knife I can recommend no other than a large plain sebenza. My 5.60
Jeff