Klipsch all the way. The Z-2300 are amazing speakers, but the volume control pod has serious balance issues that Logitech refuses to admit exist. I've traded in the control pod 5 times and finally gave up. 2 had 3-6 db bias to the left channel, the rest had 3-6db bias to the right. Yes, at some volume levels, every control pod that I owned would play one channel 4x louder than the other. Check their own forums if you don't believe me. I don't know how these models still sell after 3 years of people complaining about how bad they are. Only reason I can think of is that people go "omg THX speakers for $60 what a deal!" and read the reviews on the net (based on review samples, not off-the-shelf parts) that show how amazing they sound. Truth is they certainly are amazing sounding speakers, but they will always sound lopsided unless you win the potentiometer lottery and get a working control pod.
The Klipsch set is still easily the best sounding 2.1 PC audio solution today, despite it's age. Just don't use the in-box speaker wire. It's way too thin for good sound, but easily replaced on-the-cheap.