Personally, I think this is one of those things you buy "just in case" it helps. I thought about it a lot when first setting up my system and decided to wait to see if I noticed any shortcomings before putting the money down on one. Once I'd plugged everything in, I really couldn't detect any problems, so I decided not to invest. I do have a good quality surge protector into which everything is plugged, but that ran me about $30, not ~200.
If I bought one now, I think the primary reason would be aesthetics, but that's just because I don't notice any problems in my setup. If you're like Eric (efalardeau) and you do have issues from interference, then it sounds like a very good investment.
The only general advice I'd offer is to price shop. When I was considering these, I found the retail prices on all of these power conditioners are an absolute joke. 50% off retail was pretty normal when I was shopping.
At the time, this was the one I was going to buy if I picked one up.
Belkin AP 41300FC12. Price = $250, Retail = $750.
Here's a
link to the NewEgg page that contains significantly more information on the specs of this unit.
Jason
