I've been going back and clearing dungeons for achievements as I want to have those before the changes in Cataclysm, and it reminds me why I quit after hitting level 60 when the game first came out. The dungeons were too long and often boring as hel. As were many of the raids, with having to clear mounds of trash before seeing a boss, or just having to clear through trash just to get into the instance. That design just exhausts and bores players.
I'm totally torn on this - whilst yeah the old dungeons were bloody long and intricate the new ones can in some cases (VH) be literally one room. I had to go back to BRD for a schematic today and as I've only played it as dps I quickly got very lost and could not get where I needed to go.
Nobody could manage to get lost in the new dungeons - there a room or a straight line. But the new ones are far better for pug and emblem grinding so it's swings and roundabouts really.
It would be nice if they put in the occasional old style dungeon I guess.