The GUI and HUD are horrid. Everything is so small, and stuff is moved around for no reason again. Instead of the star power and rock meters being pinpoint indicators with actual needles or a fighting game style bar, the new star power and rock meters are now tiny glowy stripes that are more like vague suggestions of how well you're doing. That is such a step back.
Also, when you fail a song, the GUI lists "new song" way down and out of sight from "retry song." When I first failed a song, I chose "exit" because it was right next to retry, and I expected it to take me back to the song list. It took me back to the main menu. When I purposefully failed a song again to see if there is really a "new song" option, I had to scroll down the list for such a long time, and you can only see three options at once, that I actually began to wonder whether there really was a "new song" option. Apparently there is one, but you have to go down like seven times. That's so annoying. It would be quicker to just choose exit.
The thing about the interface that grinds my gears the most is that when you do go back to the song list after you finish or fail a song, the game takes you back to the top of the list every time. That has never happened before in a Guitar Hero or Rock Band game (maybe Smash Hits, I don't know, never played it). That is so damn annoying that I can see myself not playing this game as much just because of it. Now it usually takes even longer to get to a song that I want. I can't just go down the list in order anymore. Not cool in the slightest.
The game also feels kind of loose. Not exactly Guitar Hero 3 loose, but loose in that it feels fundamentallly different. It's like the strike line timing is different somehow. It can't be lag because I'm playing on my old CRT, and I already calibrated the game. It returned zero lag, as expected.
Finally, the set list is perhaps my least favorite out of every GH/RB game. There are a handful of standout songs for me, but most of it doesn't grab me. Also, most of the standout songs for me aren't technically brilliant guitar songs. Mostly repetitive chords. It's probably not representative of the other songs, but I've got to wonder how the other songs stack up. Even Megadeth's Sweating Bullets is a rather lackluster guitar song.
Here's hoping for a better game in Van Halen.