I thought this summed up my feelings fairly well:
"Summing up the music
Now most people don't just listen to one type of music and while many do put emphasis on some particular types, pretty much everyone wants a system that can deliver very good all around performance and that's just what Logitech has delivered with the Z-560 system.
I can't really offer an all-encompassing definitive subjective opinion on what the best 4.1 speaker system is for music for you as it depends your definition of "best". Having said that, as good as the Z-560 is it?s not really in the same musical league as the $450 VideoLogic Sirocco Crossfire or $300 Monsoon MM2000. Depending on what your priorities there are also less powerful systems such as the AMR-150 that can also impress but I am not aware of any that will offer the even close to the same power or deep bass extension of the Z-560. The Z-560 satellites are definitely competitive with the $100 more expensive Klipsch ProMedia 4.1 system, maintaining better clarity at high volume, particularly where there is a lot of bass. However the ProMedia 4.1 will offer greater placement ranges for neutral bass, ability for below neutral bass, slightly quicker bass response and some will prefer the high frequency response from Klipsch?s horn loaded tweeters. On the other hand, if you want to really blast your bass the Z-560 will rise to the top of the 4.1 crowd. Despite all the technical test results it?s quite possible you might come to an entirely different conclusion than me in your own personal evaluation of these systems. The key again is where possible do your own auditions."
-taken from 3dsoundsurge.com's review of the z560's
IMO the Klipsch produced a more accurate representation of the music as compared to the 560's.