First let me say I'm a big advocate of the "food first mentality." However, when it comes to the search for the best source of protein I think whey stands above the rest.
For starters, whey protein has the highest biological (BV) value of any protein source, between 110 to 159, compared to chicken's BV of 79. Now I've seen some bodybuilding articles by various gurus who claim that BV is an irrelevant measure of protein quality. Bullshit. BV is a direct measure of the amount of protein retained and used in the body compared to the amount absorbed. Gram for gram, whey compared to chicken protein, you get much more from whey.
Couple whey's superior BV with its quality amino profile and it begins to look even better. For instance, chicken contains only negligible amounts of alanine. If you don't get enough dietary alanine, your body must catabolize muscle to make it.
Yes, most whey preparations are absorbed and digested very rapidly. This is not a bad thing - it adds to the functionality of the food for athletes. I believe that pure whey isolate is actually digested slowly, so you could still utilize whey for long intervals (night time, etc.). Regardless, whey is a great tool to be utilized as such - not necessarily a food substitute.
BTW, I hate to break it to you guys - if your whey supplement gives you gas its worthless. I hesitate to bring this up because I know that for so many of you mere suggestion that those familiar "protein farts" you've been putting up with for so long are not only unnecessary, but in fact indicative of a cheap low grade product may upset you.