I've been looking for another WoW (am unhappy with the current actual WoW) and so this seems to be working out rather well for me.
Things I'm glad aren't in Rift-
1. Cross-realm dungeon finder
2. Flying mounts
Rift's visual aesthetic does have some issues but just out of curiosity did you make it to the capital city? I thought that was rather well done.
I actually loved the cross-realm dungeon finder until Cataclysm hit and then it became absolutely horrible, especially for a DPSer. 45 minute waits just to fail and have your crappy tank or healer drop party after one attempt just wore on my last WoW nerve. I do like the speed of flying mounts and recount and gearscore are useful tools, but far too heavily relied upon. If Rift lasts and is really successful, I bet money you'll start seeing add-ons for that in the same vein. I did see the capital city and it was neat enough, I guess. I just wasn't blown away by anything graphically. It wasn't awful, but there wasn't much to it either.
What I meant by the maturity of the world I meant more like it takes itself somewhat seriously. There are elf type races and people type races but everyone more or less looks like a person, no giant cartoon cows or impossibly lanky trolls with Jamaican voices. That's part of what is fun with WoW, true, but something that plays a bit more as straight fantasy is nice for a change. I'd forgotten what that kind of game world was like.
I do see what you're saying and that all is a huge part of WoW's charm, but I can definitely understand the urge to play something a bit more mature. I just don't think this is the one for me. I'm also on a bit of an MMO hiatus now so that I can actually build some enthusiasm for TOR.