I would think that a month’s time would be enough for Activision to clear existing inventory of faulty guitars. But nope. On Black Friday (November 28) I picked up a two-guitar set from Guitar Hero: World Tour, and sure enough — after 2 weeks and 18 hours — my strum bar started failing on the up-strum on the newly designed guitar.
So far so good: Activision has been quick to respond to my online warranty request. But until fixed guitars arrive on store shelves, I’d highly recommend getting Rock Band 2’s guitars instead, which haven’t received the infamy of either Guitar Hero: World Tour’s nor Rock Band 1’s guitars.
Update: On December 17 I tried calling Activision for the Express RMA process. Their customer service lines are so busy you’ll often get a busy signal once the automated response system transfers you to a live agent. This is annoying as all hell seeing as how you have to navigate the menu every time you call back, eating up at least 2 minutes of long distance time per try, and that they’re only open 9am-5pm Pacific Time. I eventually did get through, and the process was quick after that. I just wish there was a direct line to their live customer service line so you could repeat-dial the line.