I go for digital because:
- It doesn't take up space.
- It's usually cheaper.
- It's available immediately.
- Many PC's don't have an optical drive. (Our family's main laptop and my secondary laptop, for example.)
I currently see no benefit for physical.
BrandeX: Literally the opposite - that's digital libraries. I have bought the same games a few times because I forgot I had them already on Steam/GOG/Wherever...
Hey, this game looks cool and it's on sale! <BUY>
Later... hmmm. I think I already have this.... yep.
It's not literally opposite because physical doesn't prevent it in any way. Many years ago I almost bought Pulp Fiction 3 times on DVD, only that last time I decided to check before I bought, then realised I already bought 2 copies. Never watched either of them. :)
So I'd say they're pretty much equal, unless you buy at only one digital store, in which case digital wins this point.