The biggest problem we had with our '05's were the frames broke. We had 2 of them. It isn't just the '05 models either. We had a '03 that did the same thing.
Motors are very good, suspension workable. You will need to safety wire a few different places, but for all around fun bikes they are very good. The Suzuki models have a tendency to "rattle" a bit more, but we never had any issues with reliability at all (other than the frames breaking) We also raced the bikes every weekend and practiced 2-3 days during the week, so they were rode hard.