Unfortunatley there are many issues that very wildly from one bike to the next. It makes pinning down general rule of thumb maintenance advice tuff. And as Rich has pointed out before, the unsuspecting second owner is really taking a gamble.
If you do own these bikes or are going to compete on one, there is help. If you do decide to get a used one, buy it cheap enough to freshen the engine up. Kibblewhite has put serious effort into the design of thier aftermarket parts. Many of the national level bikes are using some or all of thier components. Thier spring kits, tappets, and bronze valve seats will save the head. Eric Gorr and Rich Rohrich deal directly with Kibblewhite and do impecable work for the best prices in the country, that is why they are swamped, it is worth the wait for the precision needed to do these heads right.
To be on the safe side cranks should be replaced with pistons (cringe) especially if you are running a higher compression. It is really nice to have the entire crank done up if your seriously competing. 04' flywheels should be changed out as well.
Oem cylinder specs and plating quality is all over the place. It is nice to have your cylinder set up with good plating that is honed properly (see Eric and Rich). If not check your new one out before installing for fittment and quality assurance.
Cases are light and flex alot with the frame. Keep on tip of the hardware to prevent leaks and damage. Many drain plugs have mysteriously come out, safety wire it or check it often, it is drilled for safety wire.
Eric, Rich, and Mike at Kibblwhite have saved my butt more than once, thanks gentlemen.
These bikes run and ride sweet when they are right, but they do take attention.