The research about PWO supplementation is very extensive. There is no doubt a good combination of fast digesting protein/amino acids and glycogen replenishing agents (whether some kind of a carbohydrate source or unique combination of individual amino acids like L-Glutamine) can produce positive results and a faster recuperation.
The latest in PWO trends is a customized amino acid blend based on your ION panel (take a look at ttp://www.metametrix.com/TestServ/default.asp?PageID=1 especialy the fasting plasma Amino Acids) It can make a huge diffrence in recuperation, as it goes straight to the source and helps with your deficiencies.
One thing about PWO supp', though, is that there is no long term reasearch about it, and there is a claim that after the first couple of weeks of extensive use of PWO procedures, the body adapts and they lose some of their effectiveness. Some people, due to the mentioned above, decide to go the liquid PWO route only after the most deplenishing workouts and that way, keep the effectiveness.
Another issue is health vs. fitness. Liquid PWO and a high glycmic load seems to be not the optimal choice if your health is your first priority, but Robb would be the person to consult here.
I hope this helps.