The quirks of World Tour mode are bugging me less as I've gone along, and some commenters were correct that Challenge mode seems to do exactly what I wished World Tour did, presenting chunks of songs in increasingly difficult tiers. I still think you shouldn't have to unlock songs if you want to play them with your friends, but we're stuck with that for now.
Otherwise, the gameplay is just terrific. My drum skills are at the point where medium difficulty is a little too easy, and hard difficulty is just about within my range. It seems like Harmonix has calibrated the difficulty levels exactly -- the toughest songs on medium seem about equal to the easiest songs on hard. It's a simple and logical progression for the low-talent drummer. (By the way, I tried using the drum trainer and it seems like it's helpful, but less helpful than learning those same patterns in the context of songs you know.)
I had my doubts about whether online play would work for this game. Not because of the precise timing required -- latency was probably a bigger issue for the original Halo than it is here -- but because I thought at least half the fun of playing Rock Band is doing so with other people in the room. That's still the optimal setup, but playing with friends online turned out to be a blast. I think it helped that we both had avatars that looked (somewhat) like ourselves.
There are so many songs available that it's hard to criticize what's there. It got easier to skip some of the worse songs as I progressed through World Tour. And there are some real gems, too. It's nice to finally see the Replacements and Dinosaur Jr. get their due in a game like this. I might have picked a different AC/DC song, but other than Led Zeppelin there is no band that needed to be in the game more. And one day I will tell you about the time I played the solo at the end of "Alive," and in the process became a being of pure light.
Without having the original drums handy, I can't tell if the new ones are any quieter. They still seem loud, but it's more of a rubbery thud than the high-pitched clacking I seem to remember from the first kit. So far, the neighbors haven't complained. These drums are supposedly "velocity sensitive," and I'm wondering how good a drummer you need to be for that to matter at all. I'm still at the point where I accidentally miss the green pad when it comes up. The kick pedal still slides back and forth along its bar, too. I need to appropriate the solution my friend Pat came up with and clamp it in place.
Finally, that gorgeous guitar. Without question, it's the best-looking fake plastic guitar controller I've seen, and at this point I've seen more than I ever expected to. Feels great, too. The problem with the original Rock Band guitar was the mushy feel of the strum bar, compared to the precise "click" you got from the Guitar Hero axe. You still don't get that click, but the edges of the strum bar's range feel more solid this time. It's easier to play those fast strumming sections purely by feel. Initially, I also had trouble shifting up and down the neck without spaces in between the fret buttons to guide me, but as I've gotten used to it I think this design actually makes it easier to slide back and forth quickly.
It is still hard to escape the feeling that this isn't exactly a full-fledged sequel, and more of a spit-and-polish, but I had that same initial impression about Guitar Hero II and look how that turned out.