Belts are fine to a point, power is not their forte i.e. an FZ1000 (140ish) is pushing it I'd say.
Check adjustment about 5k, Harley's are said to last up to 100k although I've never seen that. Average 30 - 40k like a chain it depends on power and how you ride it, they're so much quieter too. There's no snatch in the belt, so much smoother ride, gear change and low maintenance, that's often their down fall, owners for get them and they snap.
They just don't like too much water/mud/grit/sand or too many wheelies, they're also impossible to fix if they snap, replacement only, no adding a link to get you home etc.