Yeah… I've got an ACD but I never noticed any reflections because I always take care of putting screens in the right places in order not to have them.
I was in the store the other day though and went to play a little with the new iMac. Looked nice. I then went to see a TB Display (mine isn't TB) and was shocked to see the difference. Isn't huge, don't get me wrong, it's just that I wasn't expecting any difference and there's some.
So yes. Less reflective. Still is, but less.