Also HS gives you a warranty for life (regradless of manufacturer's warranty). I tested it recently when my wife's iRobot broke after 4 or 5 years of faithful service. No questions asked - just send it back for a replacement.
But as to the PoolBuster - I have hesitated to buy one because I keep reading that the housing is not waterproof (as it should be) and after a year the motor goes bad and/or the battery goes bad from water intrusion. And repalcement of those costs as much as a new cleaner.
Hopefully the manufactuer will pay attention to these complaints and improve in this area.