Well, I cannot comment on the Cain and Cain, but I do know that many people who have tried the Teac with single driver speakers are VERY pleased with this little amp.
I am one of the people that uses this amp, but with boring old two way low efficiency speakers - I love this amp, and that is the stock one - there are several folks (Bolder and others) that mod this amp.
I will report back on the transformation when I receive the amp.
Dmason might be able to offer an opinion, I believe he has some experience mating digital amps with high efficiency single driver speakers.
So far, for me, the best $99 I have spent...
mark in Canada