I am not aware of any major malfunctions like the ones you've had. 4 times since 2010, that's pretty insane. Did they replace the whole system, or just speakers? I am also not aware of Jacuzzi/Sundance moving away from JBL, I have a J-425 in my showroom with the system and it works perfectly. What has your dealer said, maybe you could talk to the Sundance RSM? I'd have customer service look into it.