With the last character I started, I decided that as soon as I was done with all of the quests/missions in the seared areas around Ascalon, I'd try to walk him as far as I possibly could in the game rather than doing missions to advance across the map.
Did lots of quests along the way for XP and whatnot, just none of the missions. It's been the most fun I've had playing the game yet, without question -- I'll definitely be playing my new characters this way from now on.
Started at Ascalon City, and I hit lvl19 in Riverside on the weekend (so I'm almost done :|). I've just started to go back and do some of the Shiverpeak missions for a change of pace.
It's not like you'll see a whole bunch of stuff you've never seen (although there
are quite a few spots you might not otherwise get to), but you might find a slightly different way of accessing it to be refreshing.
Highly recommended!