Sound of chip amps / gainclones?

Has anyone tried chip amps like those from chipamp.com or audiosector.com? These are similar to the 47 labs gaincard amps and use an LM3875 chip. How do they sound compared to other types of amps? I am concerned about dynamic range, and brightness/HF ringing.
I am looking to build one for my 4" dia, 8 ohm single driver speakers and need about 6 watts.
Thanks