My Pool Vac Ultra is in need of a bunch of parts (again) so I was considering the 2 Wheel Pool Cleaner. The PVU always seems to be in need of something and was wondering how often Pool Cleaner owners are having to replace parts? What are the weak points (if any) of the Pool Cleaner? I saw that it was $359.00 at Backyard something or other with free shipping. Any experiences with them?