they are one of the best brands out there period, even their factory installed premium systems (chrysler) sound pretty good
their subs don't handle extreme amounts of RMS wattage but they sound very clean, they have a lower frequency response than most other speaker brands so they play lower/deeper bass, not to mention they have higher sensitivities than most brands also--
all of their sensitivities are over 91dB and the average as about 87dB--- a speaker that has a sensitivity that's 3dB higher than another will only require half the RMS wattage to achieve the same amount of sound/volume
they are a CEA-compliant brand which means that their amps have been tested and produce or exceed their advertised RMS wattage with minimum distortion and as a rule if they make good amps they make speakers that can handle the wattage from their amps
p.s. whoever said they weren't a good brand is clueless