I just recently switched from my Ping I3 Blades (actually cavity back) to Mizuno MP-37's and I really didn't notice that big a difference in the mis hits. The feedback and thin top line I get from the Mizuno's is what I really like about them.
As far as the knockoffs are concerned, I wouldn't use them. Stick to the Big Bertha's. The quality control of the forging process, I would bet, is not the best. Not to mention the lofts and lies have been known to be off significantly on knock offs.