I would NOT recommend these to anyone, even with the PRO's I mentioned. The control unit for the Z-680 is on its 4th revision already, as the components inside it are failing left/right. I have had 3 of the 4 different revisions of the control unit at this point.
Basically all the audio "processing" is occuring in the control unit, so when that thing goes bad, you are SOL. Logitech support will replace it if it is under warranty (they know the units break), but it is a pain in the arse to mail it to them and wait 4-6 weeks for your replacement. On top of that, of course, you are paying for the shipping to California, and for the long distance phone call to support
Logitech support has told me that they are no longer developing "high gain" speaker systems, as they had too many problems with the Z-680. They blamed my failures on the fact that I listen to them on "high volumes", which is total BS. I haven't ever had to turn it up past 60%, and I hardly even use it...
I now have a custom cooling fan mounted on the control unit to help keep it cool, incase heat was ever an issue with it. At this point I have to baby the damn thing and keep my fingers crossed it doesn't break again because I am now out of warranty and I don't think they will fix it again

MY ADVICE: Save the extra $$ and get a true name brand receiver and some decent speaks
