I have heard both and they sound fairly equivelant to me.
One note, because the SoundSticks use USB and require a Driver, with almost every maor update to the OS the sounds gets a little better. The difference from 9.0, to 9.1, to 10.1 to 10.2 is pretty amazing.
If asthetics are very important, well, most computer speakers are pretty ugly.
If you are really concerned about sound quality, give the Klipsch desktop speakers a listen, and compare everybody else to those.
JBL is a subsidy of Harmon International, which also owns Harmon-Kardon. So, the technology is essentially identical with either, you're just comparing how they implement it with the two products. They probably come from the same factory.