Well, I bought Episodes from LC on a separate disc, so it would be a little more fuss loading different characters, but I see where you are coming from. It doesn't lessen my anticipation, though, knowing V is an evolution and intregration of the trio elements from IV. It's R*, after all. At the same time, you can't dismiss gameplay for not being revolutionary enough until you've tried it.
And I happen to agree with you about the map. There's nothing quite like that moment when you finish a turnkey mission only to discover you can finally explore a whole new region of the map.