"Enhanced Edition" - no. They updated the resolution and probably removed the (now useless) performance-vs-quality options as well as a few visuals. Other than that it's just a few tweaks and features, but the whole engine (!) seems to have stayed the same - especially the netcode.
How is that a problem? Well, the game crashes frequently, multiplayer is unreliable and lags, and the game freezes on various occasions (saving/connecting/transferring items/etc) that should not let a modern game freeze. Well, I thought that at least, regarding the "Enhanced Edition" suffix.
I played BG2 in multiplayer before, and the UI is almost exactly like it - a good thing. But to my disappointment, all the bugs haven't been fixed, instead this game actually crashes more often than BG2 original.
If it is reduced, you like RPGs, and you plan on playing singleplayer only, get this. Otherwise, better not support this attempt on getting money with a slightly updated old game (their only work was to fix/enhance the game - and they failed the first part).
I feel like I should add that you get the "DLC" for the game (2 new chars, sound and icon packs) for free on the Steam edition.
Seriously, did you even test the multiplayer before shipping?