So, the mic looks exactly like RB's, the cymbals on the drums may well get in the way on the more difficult songs (transitioning to them will also be a huge challenge, plus the set looks more flimsy that the RB set. On RB, there is a lot more floor support and the vertical supports appear to be twice as thick as those of GH:WT), and the guitar is a direct copy minus the buttons looking like part of the guitar, rather than buttons. Honestly, it has the same shape, they added the extra row of buttons just like RB did. Plus the guitar is missing that little switch on the bottom that allows the sound of the guitar to change. Truly, it looks as though from a controller standpoint, RB has GH:WT beat.
As for gameplay, customizable characters seems pointless for the sole reason that you never look at them while actually playing. I agree that the other things RB lacks are inexcusable, but to me it looks as though RB is still a great game.