I switched from old physical auth to this one - one less thing to carry. great. That also forced me to switch to battle.net account - which would be great if

a) you could switch from 1 wow account to another from some ui - click back just sends you back to login

b) after using a toon - trying to switch realms just hangs; forcing you as well to reenter password

Note: it saves your (sub)account name too under your battle.net one when you check the "remember account" box - which is fine for me