I used to care about the metallurgy but now I realize that the chemical composition of the metal is just the tip of the iceberg. It's a "necessary" but not "sufficient" ingredient of a good knife.
I'm now of the opinion that heat treatment is a far more critical component in the blades performance, to the point that a less expensive, "low quality" steel can outperform a more expensive steel if someone has really paid attention to developing a high quality heat treatment process.
I have/had excellent blades in 5160, 1095, O-1, A-2, SR-77, INFI, SR101, AUS-6A, AUS-8, etc. There seems to be a fashion element in every new steel that each knifemaker wants to capitalize on with new marketing buzzwords. Indeed, if you look closely at the chemical composition you find that many of the "new" steels look a lot like the "old" steels chemically, they just have slight differences and new names. What many knife makers will claim but rarely substantiate is whether or not the slight chemical differences really have a significant difference on real world performance. Note that INFI, with the nitrogen substitution, is very unlike many other commercial knife steels.
I eventually came to conclude that rather than try to play amateur chemist/metallurgist (I hated chemistry btw) I'd rather listen to folks like Horn Dog who beat the crap out of the knives on a comparative basis and express their satisfaction/dissatisfaction. And I try to chip in by drinking a beer while reading their posts <img src="/ubbthreads/images/graemlins/wink.gif" alt="" />