OK, I've played something like four or five hours of CoH, and I have some initial impressions:
1) Faster Downloads. Perhaps this was because I'd bought a later edition of the game (up through Chapter 7, they are now at 11), but the updating took *much* less time than with even the Burning Crusade expansion. My one complaint is that the splash screen doesn't do a very good job of letting you know that the updates are done - it looks pretty much the same, just with 0's to let you know that the updates were completed. Of course, with WoW, you had to quit, start the game again, then find out you needed more updates. Multiply by, oh, fifteen for the base game.
2) Weaker graphics. I have *not* ratcheted up the resolution yet (it required a restart that I didn't want to sit through), but I suspect that even with more pixels the cars will still look a little like something from Duke Nukem. Even the original WoW areas looked much more polished, and the new ones completely blow CoH away. I understand it's difficult to differentiate urban areas as much as natural ones, and even WoW starts to look a bit samey after awhile (oh look, another ogre camp).
3) Character creation. As advertised, this was a very cool process. I ended up with a magic scrapper, Spellweaver (although she has very few spells at this point). Breasts at the lower setting - plenty. Waist at the highest setting - pretty skinny. This cracks me up, but I do understand that we're talking superhero comic book standards. She's pretty short, around 5'6", very dark costume with a hood. Actually, it was the hood that inspired almost the entire rest of the character. I'm looking forward to trying this out with a variety of characters.
4) Friendly players. I've been asked by around 10 people to join groups in four or five hours of play on a server with light activity. This *is* in the newb zone, but I consider that to be pretty good for a start. I haven't joined anyone yet, mostly because I prefer to get a grasp of the environment on my own so that I can try things. I expect I'll avoid people who spell their name "warrier" though.
5) Interface. A little clunky. Not really enough slots for powers, at least in the long run (WoW gave me more than double, if you include the extra slots that you have to activate). Close buttons are *tiny*, fortunately most are closable by clicking on the button you used to open it. Otherwise things are very similar to WoW in terms of what you have to do to use powers, etc.
6) Environment. I like the general enhancement idea, although to be honest I ended up discarding a bunch of low level enhancements early before I figured out I could sell them. Duh. Because they aren't physical things like potions or fuzzy bunny tails or gnarled teeth, I didn't think of them as "stuff". I suppose I could sell Inspirations too, although I like hanging on to those if I can (especially health buffs). I haven't figured out inventions at all yet, but they strike me as being very similar to alchemy or engineering in WoW, just differentiated out from enhancements (in WoW, everything "looks" the same until you realize what you can and can't use). The fact that I can't loot the corpses of the generic gang members I've beaten up is annoying! And yes, the quests all feel pretty much the same, and the buildings are mostly forced march linear affairs with few choices to be made. But it's early yet.
7) Gameplay. I love the idea of calling your contact. I hate that you can't seem to get nearly as many quests early on like in WoW - you could get quests that piggybacked nicely. At most, I've had two missions going at once, and most of the time a contact gave me a choice of quests. It's that management of quests that I've generally liked in WoW, this "do one thing, run back across the zone to the contact to get another, run to another part of the zone" that I haven't, although the Call mechanism seems to be making that easier once you have enough cred with said contact. Of course, I'm only on level five or six at this point (I can get a starting character out of the newb zone (level 6) in about an hour, up to level 10 in about three in WoW, for comparison), but who knows how well these things track.
8) Overall Impression. It's very early yet, and I've only played for a couple of days. I have a feeling, though, that this may not be the game for me. I'll definitely give it the full month, and try both heroes and villains, but I don't have that feeling of magic and the excitement of finding out what will be around the next corner. Maybe the world is too close to what I live in, with people and streets and buildings and only the caped crusaders stick out. A real test will be going back to WoW and seeing how much I prefer (or don't) playing in that world.
Again, all of the above are initial impressions. I haven't even started to make up my mind yet about how much I like the game, but I'm certainly getting my $14.99 for the disk and one month of gameplay out of it. I am very tempted to give GW: Nightfall a try as well, although I think I'm better off sticking with a single MMORPG at a time. When does Conan come out again?