These are the logitech ones
http://www.logitech.com/index.cfm/speakers_audio/home_pc_speakers/devices/250&cl=ca,enThese are the JBL ones.
http://www.play.com/Electronics/Electronics/4-/3360738/JBL-Creature-II-Alumnium-Self-Powered-Satellite-Speakers-And-Subwoofer/Product.htmlThe JBL ones have a wider frequncy range (50-20, as opposed to the logitechs 35-20) and a higher powered sub (24 watt rather than 23).
The signal to noise ratio for the JBLs is 80db while the Logitechs is 92.
Do these figures make a difference?