Just wanted to throw out a couple of bugs/few suggestions:
I had the game freeze up in the middle of playing the Kelly Clarkson song for that "Hard Goal is Hard" dealy. Just froze completely, had to turn off the 360. Nothing unusual going on, and I know that's not particularly helpful with a lack of details, but figured I'd throw it out there.
There's something strange about the audio signal being sent out during calibration. When I was doing the audio lag calibration, I could only hear the click about half the time, and my amplifier was going nuts switching audio modes. No problems at any other point in the game, but it did make audio calibration a little challenging.
Not sure if bug or by design, but my recommendations appear to be...lacking. For the score battles, it's constantly picking the same three users for me to challenge - none of which are actually friends of mine. I'm kinda feeling like I'm picking on them at this point. Also, after playing a few songs, every single one of my recommendations is to "Get More Stars" or "Play It Again". It'd be nice if at least one of them was a new song, and there seems to be a lack of variety in the recommendations. After I did the medium Foo Fighters goal, every single recommendation was a Foo Fighters song - I just played a ton of them, I don't really want to play a bunch more. I'd like some new songs because I tend to have an issue picking out a song I feel like playing, especially if it's one that I neglect a lot, which leads to...
Can we get a Random Song menu item in the song list? I use that constantly in RB3, and am really missing it.
Edit: Somehow, I truly missed it. I have no idea how I didn't see it, and my head, it hangs in shame.
Finally, it's probably been mentioned (I haven't gone through the whole thread yet, but wanted to get this out while the suggestions/bugs were fresh in my mind), but can we get rid of that whole "Press A to start" prior to the discovering of DLC and connecting to Rock Central? It's nice to be able to start the app, go grab something to drink, and have it ready to play - having a needless button press right in the middle of it is kinda irritating.