I'm currently happily playing SWTOR

and especilly Taris feels as being HUGE ! (I'm not much further than that, though.)
I haven't played any of the Elder Scrolls games yet, so I can't judge.
I believe, however, that for some people a smallr world is sufficient, whereas other people want rather a bigger world.
And then : Let's not forget the aspect of Detail ! : A richly detailed environment where there are always new things to discover are - at least in my personl opinion - alw<ys a great thing !
The bad side of this is, that the bigger an environment is, the mire difficult it is to place all of these little, neat detals into this world ...