I pretty much just listen to 2-channel stereo. But from what I understand, the logic that process the surround channels isn't going to send low frequency information to the surrounds anyway - they ALL go straight to the sub. So I really wouldn't worry too much about frequency response.
Surrounds are supposed to provide diffuse sound to create ambiance. Since these radiate in 4 directions, I imagine they'd be pretty darn good at it. They aren't terribly large, either - so you can always take advantage of the 30 day home trial and you won't be out much money if you don't like 'em.
I'm not an expert, but nobody else has really replied.
