Rear brake drums can go oval - check to see if the pedal pulses when you (lightly) apply the brake.
One of the cam followers wears (and takes the cam lobe with it) if oil changes are not regular (I'd say change the oil at 1,000 miles). Listen for a tappety noise from the rocker box.
Apart from that they are great and can take tons of abuse. Spares are cheap and the performance is fine for most. The front brake is good and the chassis is more than stiff enough for the power produced. I can do a service on mine in under an hour... all by myself (which is saying something!)

You can get away with slightly shorter shocks and dropping the forks through the yokes (no more than an inch though, and that's dependant on what exhaust is fitted).
Any questions, send then my way
GC