Actually I dont see any improvement since GH3, It's the same thing. In all honesty, take a 2 year break and come back with a huge update.
I prefer to wait 2 year and have something incredibly cool and never seen before instead of buying 5 versions of the game with different characters and songs.
I really dont see why they dont make Expansion TrackList Pack with about ~20 new songs, then you copy it into your X360/Ps3/Wii hard drive then load it with your main guitar hero game.
That would be more interesting, instead of releasing something like:
OMG LIKE THE NEW GUITAR HERO IS THE SAME THING AS THE PREVIOUS ONE, BUT GUESS WHAT!!!! WE ADDED A SUPER COOL NEW GIGA TOP PRO CHARACTER AND ONE SUPER MEGA COOL SONG!!!!
The only big improvement from Guitar Hero franchise was the ability to use drum and microphone, and it was ripped off rock band
Still Guitar Hero is very cool and fun to play, but we need something more. It gets old and repetitive.
They release about 5 guitar hero games every year. And that's too much, espiecally if it's always the same **** thing.