Well, I use it with water after my workout. The milk takes a while to digest, and if your whey is absorbed in the milk really good, it'll take longer to absorb, or so I'm told.
The vanilla isn't bad with water, but the chocolate sucks if you're not taking it with milk.
But, I take it with milk in the morning and at night so it's slow absorbing throughout the day.
Oh, and BTW, I, by myself, probably drink close to 1/2 or 1 gallon of milk a day. It's hard for me to get my protein because my parents really control my nutrition budget, but they're anxious to buy more milk, so it's my best source of protein.