I've seen Bowie loads of times and have yet to see a disapointing performance. Every showhas been amazing....If you've never seen him live and you're a fan, then you really should go.
I think the advantage Bowie has over the other 'old-timers' is that he's aged gracefully, so you won't see a 50+ year old man trying to be the sexy rockstar...unlike Jagger and the rest.