I have the klipsch promedia 5.1 ultra's but im looking at the logitech z5500. Would the upgrade be much of one or are they pretty much the same?

thanks, mike

heres the 2 specs

Klipsch
http://reviews.cnet.com/pc-speakers/...1.html?tag=sub

logitech
http://reviews.cnet.com/pc-speakers/...6.html?tag=sub