All of the models are very nice, I own an 04 500 H.O. Polaris. I am very happy with it but, one thing I would highly recomend is fuel injected. Being I use mine primarily for ice fishing I would not buy a carb model, (This is why I am considering trading.) I have not had starting problems, it would just be nice to not have to mess with chokes. Also look at what you plan to do with the machine before you buy, I got all the bells and whistles and for going out on the ice I could have gotten by with a cheaper model. If you trail ride then you definetly want suspension. One thing I will also mention is the 4×4 option. Having tru 4wd during ice season and deer season makes for a nice option, many of the machines are really only 3 wheel. I am really happy I put on Rawhide tires, and the winch will also come in handy.
The only machine I had had bad experiences with is the Artic Cat models.