I have an older Panamax 4300 which is still in use in our bedroom.No problems with it, with or without it I can not see or hear any difference. bascaly it is an exspensive surge protector.
I use a APC J15 UPS on our main system. Battery power kicks on every so often letting us continue to watch TV , or listen to music when we have power outages.This alone make me happy with it. http://www.amazon.com/APC-J15-Theater-Ba...5290&sr=1-1
Does it condition the power leading to better sound /vision ?
I have no idea.
It is worth a look at the APC S 15, it is the big brother of the APC J serries. Amazon has it very very cheap
http://www.amazon.com/APC-S15-900W-Power...5937&sr=1-1