I agree with the suspension comment. Out of the box they just do everything from the word go, but the standard springs sag out very rapidly when a larger tank goes on. The suspension was the best money I've spent on it, it not only retores the handling but the ride is rather good too for an older type suspension.
I forgot to mention before I addded a braided brake line (the rubber one turned into expandomatic) and a Braking wave disk on the front. Rear disc is now warped and shot (I'm not surprised) so that one's next.
I also added a light-action clutch lever which cost a whole $14.95, and it makes a considerable difference to the riding enjoyment and fine clutch control. I still run the original grips and throttle, and I only replaced the original cables because I found a single strand had let go after 10 years. Not bad considering the environment these things operate in. A little simple maintenance is all they require for long life and reliable service (unlike my KTM, which is almost like sevicing a road bike).
My chain and chaingang sprockets have done around 30,000 k's now and are starting to show signs of terminal wear, so replacements will be in order, but if I can get another decade out of the replacements I'll be happy. Overall, the bike has been cheap as chips to own, a breeze to work on, and a hoot to ride.