The steel on the ritter is not exactly better. I, and many people prefer 154cm as much as s30v. So it really boils down to which lock you prefer and what your gonna use it for. Both are of equal quality. But the ZT definatly has more features. I prefer the grip just becuase of the axis lock being an extremely stronge lock. But the Zt linerlock doesnt fall that much short. Depends on what you want to use it for, different specs. The ZT is large and heavy, The grip is a bit smaller, more sheeple friendly and definatly lighter. If you have a chance handle them first, do it. Huge difference in each knife.
As far as which one i would buy, i would go for the ZT-0200, Only becuase i prefer the standard Griptilian 551 over the ritter grip, as i prefer the 154cm. The ZT- has the edge on heavy duty feel, but i still prefer the axis lock. However the Grip 551 is just as much of a knife for half the price or the ritter, And the blade shape is much more utilitarian. Perfect EDC. ZT=Scary EDC
Matt