There is a sigma nutrition podcast from a couple of years ago with a researcher who compared whey to casein before sleep, and found no difference in the absorption. I believe casein can cause more issues for some people than others. No discernible difference for me.
Personally, I’ve been flipping between “milk protein” and Protein Blends most of the year as Whey has gone up so much in price. Can’t say I’ve noticed any difference in how I feel. The milk protein doesn’t mix as well with yogurt though. Next order on the way (whey?) is Whey (the best offer available - ltd edition random flavours!).
My formed opinion is that they type of protein doesn’t really matter (unless you’re getting into the likes of collagen). Days I get enough from general diet (which is admittedly rare) I don’t supplement at all. I’m not claiming to have anything to back that up scientifically though!