I'd like to stick up for the Crown !!!!
I've used an XS500 as a power amp behind a number of pre-amps (ampeg, line6, behringer etc) through a variety of cabs (mark bass, eden, marshall) and have absolutely no issues with it whatsoever, it's a pretty transparent amp so the real colour comes from the pre and the bass.
That said, I've not used it through 2 cabs at once - but imho for the power it supplies and price you can get it for it's a winner !