You can make good gains with pretty much any eating plan, provided you've got enough calories and protein.
As much as we'd like to self-analyze these plans and recommendations, there are often so many other things involved that it's really hard to know how they'd play out in real life.
Take the discussion in the link. Bip points out that most pwo studies start with nothing eaten recently, before the workout. Who does that in real life? Eat two hours or more before a workout, and that energy is still there, even if your belly is empty.
Even a lot of the studies that Bio-test used to promote Surge! as the best pwo drink use studies where they started in a fasted state. I don't EVER want to be fasted, much less before working out. Were the results of these studies important? Sure, but you still have to rely on people putting things into practice to see what happens, the correlate the data in the studies with those results.
IMO, all of these studies are somewhat mitigated by eating every 2-3 hours, having a decent amount of P with each meal/snack. With this happening, you will have a constant stream of P in your body, ready to make some muscle, at all times.
I still think a PWO drink is important (and that Surge! is likely one of the best ones), but if you do all these other things, the content of the drink is less important. There should be plenty of P, some C, and not so much F. The difference between whole and skim milk's not that big, fat-wise.
Sure the F slows "gastric emptying." Okay... Two problems. You won't be hungry again, as quickly. This is good or bad, depending. Also, the P won't get digested as quickly. But, if you're eating P every 2-3, you already have plenty that's ready to go, anyway.
Whole Milk vs Non/Low Fat Milk
This pro-low, for kids, and they show the "significant" differences. IMO, it shows how insignificant it is, for those who may be bulking.