The z560s may be solidly built, but they are not made with any sort of quality. If you knew the amount of work it took to get the damn sub open, youd be amazed. Theyre heavy, they look nice and solid, but internally they are junk.
I have never ever had a set of multimedia speakers blow out on me. Until I got the z560s. They were not misused in any way. Just blew out on me, and they werent even playing that loud. I saw everyone complaining about how easy they were to blow, how they had to RMA blah blah. I thought not me, I don't abuse speakers, I wont have any problems. Wrong.
That was 2 months ago. To this date, I'm STILL waiting for my replacement, logitech themselves have it on backorder. I asked the CSR why, and she told me because they didnt expect to have to send so many replacements out.
Most people probably wont have any issues with the 560s. If you dont abuse the knobs, you wont have any trouble with that. If youre not concerned about absolutely transparent sound, the z560s will make you very very happy for the money. But be warned, and dont cry when they blow, because theres a damn good chance they will, and you will need to get a replacement set of speakers on your own.