Guitar Hero was Harmonix big Rhythm Game branding before they went their own way to create a bigger whole band experience in Rock Band.
Activision, the IP owner for the Guitar Hero branding, choose to continue the franchise using Red Octane to develop in to the same full band with karaoke as Harmonix.
In truth their is very little between the two games and the preference is largely going to rest on the choice of songs. I personally really digged World Tour’s set list with favourites such as Hotel California, Go Your Own Way and Band On The Run sitting nicely alongside The Smashing Pumpkins, Oasis, and Coldplay.
There’s a more career and story driven focus to this game which I found set a better overall focus to the gameplay and allowed for a more concentrated single player experience.
The other really nice feature is the ability to re-use expensive plastic instruments from the rival game so the player doesn’t need to re-empty their bank balance getting properly equipped. That said, if you splash out for the official drums you get an better layout with an extra pad and a more natural symbols layout.