Guitar Hero: aging disgracefully, or better than ever?

The Guitar Hero series would have to rank as some of the greatest games ever made. Simple to learn, but fiendishly hard to complete (on expert difficulty), the games have something for everyone. I was hooked after playing Guitar Hero II on Playstation 2, and thought that I would never make it beyond medium difficulty. Well, it wasn't long before I was working my way up through hard and expert, and seeking more songs I purchased a copy of the original Guitar Hero. Another great game with an excellent selection of classic songs, although the controls did seem a little unforgiving compared to Guitar Hero 2 (they must have finessed them for the sequel). I loved every minute of GH1. Actually, perhaps not every minute... trying to beat Cowboys from Hell on expert still makes me want to throw my guitar through the TV.

Anyway, my (elusive) main point is that since Guitar Hero 2, I think the series may have lost its way. Guitar Hero Encore: Rocks the 80s was a disappointment... at first. Nothing much had changed since GH2, except for the deletion of bonus tracks. Not a good start. However things rapidly improved, with the inclusion of some fantastic songs. Wrathchild by Iron Maiden anyone? The top-notch tracks were the saviour of GHE:RT80s. Guitar Hero III: Legends of Rock, however, went right off the rails. The fundamentals were all still there, and the track list was decent, but the game just didn't have the same feel as the prequels. The one-liners and tips that appear during the game weren't funny anymore, and the in-game graphics had undergone a wholly unnecessary makeover. Why did new-GH-developer Neversoft mess with a winning formula? Why couldn't original-GH-developer Harmonix crank out one more Guitar Hero themselves before moving on to Rock Band? And while I'm asking questions, why am I still stuck on 31/40 songs completed (expert mode) in Guitar Hero 2?

So many questions...