Some people have a hard time digesting milk, others don't. Some take "lactaid" along with it and are fine.
The thing is this: milk protein isn't indigestable, but it does take a long time to digest, which is good and bad. Bad, because it lays in your stomach -- good because the nutrients are released slowly, making it somewhat anti-caatabolic.
Milk, like all dairy can smooth you out, so if you're cutting it isn't a great choice but I think milk is excellant if you're on a bulking program. Mixing your protein shakes with whole milk works like a charm for growth. After all, it is natures "growth food." Some people will say it makes them fat but if you're an ectomorph, it shouldn't be a problem.
Milk also contains lactoferrin, colostrum (tiny bit) and is pretty high in BCAA's. And if you want to believe what Rheo Blair said, lactose is the ultimate carb since it's animal in origin as well as highly insulogenic which forces ntrients into the bloodstream very effectively. (Another reason it causes growth?)
Besides, what else are you going to wash down the Detour bars with?