Dob,
The answer is; very well indeed. Even H2O's entry level Signature 100 stereo amp is stable powering the Apogee's midrange panel (0.3 ohms)- and can effortlessly do so might I add.
Sound quality? Thats as subjective as it gets. Personally, its one of the few ICE amps I've heard that I can live with.It's also one of the few affordable powerhouse amps I've come across that can sound as delicate as an integrated with an extremely simple and small circuit (ala, red wine audio sig 30). As always, this is all my own observation - so take it as such.
I'd recommend H2O Products, but they are disqualified for being relatively large, and quite heavy. Thankfully, there are plenty of slim line ICE options that are suitable for HT use. Wyred4sound, D-Sonic, PS Audio, etc.. etc..
Good luck with the class D hunt Docrobbi