CoH/CoV expat, who was disappointed with the buggy pile of crap NCSoft released and tried to call a game, so migrated over… (This is from a warlock player’s point of view. We’re kinda squishy. If you tank it up, then you’d have a different play experience)
CoH/V is much more linear than WoW. You’re able to go where you want, sure, but the contacts tend to lead into each other a lot more. In WoW, you get your quests wherever you finds them, which somtimes can lead to a lot of stumbling around going “Have I gotten all the quests in this area?”. The biggest difference I’ve found, and the one that gives me the most trouble, is that you can’t queue your attacks. If you’re performing another action (attacking, casting a spell etc. etc.), then you can’t do anything until it’s done. For someone used to lining up a bunch of attacks in a row (like in CoH) it can be a bit annoying.
Conning is basically the same - your grey mobs are too low for you, worth no XP. Green is easy to take, yellow’s a bit of a challenge and orange/red are getting to the point where you need help, or need to level a bit.
WoW seems to be much more group-oriented, too. Where you can solo CoH/V for most of the game if you’re so inclined, there’s points very early on in WoW where you’re either going to need a group (so it may be good getting into one of the servers where the dopers are, so you’ve got a readymade group of people you trust), or you’re going to need to out-level the mobs in the instance by at least a good three or four levels (and even then sometimes get your arse kicked).
And the walking. So much walking. Backwards and forwards and up and down. The world is bigger than CoH/V, as you’d expect. But the game is highly addictive. It has the whole “Just one more quest/level/artifact and then I’ll go to bed/work/school” thing going. And you’ll keep walking until you get that quest/level. If you like the fantasy stylie stuff, then it’s a great game.