Hey!
OK, so what would be the perfect system or partner components for this type of amp? 
Take care,
Buddy 
That is a damn good question. Unfortunately, there is not a good answer.
I can give you some feedback on what most owners of our stuff have:
A lot have Maggies. Nice, flat, predictable impedance. The strengths and weaknesses of each seem to go well together. Besides, in the case of our products. we tweak them to sound right (to our ears) on them.
A lot of guys think that they go better with tube preamps, or our (older and no longer produced) JFET preamps. Some "midrange magic" seems to be added in that way. (We think that is more a function of the distortion spectra of Class D amps is different enough that some extra 2nd order harmonics need to be added back in somewhere along the line in order to sound more in line with traditional expectations.)
Here is what I would say they might not go with:
Low-impedance speakers (2 ohms or so.)
High-impedance speakers (16 ohms or so.)
Horn loudspeakers.
Too much variation in FR for the first 2, when compared to our reference. Horns..........well, no one here likes horns, and so when we heard our amps on horns.......well, 2 wrongs didn't make a right!
Speaking of reviews in general...................
They all need to be taken with a grain of salt. Reviewers' taste in music and reproduction, as well as the quality of their system and room acoustics, is not likely to be yours. Add to that............if you ever take note........a lot of them don't keep the same system very long! While I have never personally done an exhaustive study of this, I do know that a lot of them have a way of getting cables and equipment into their systems that was reviewed somewhere along the way.
And then something new comes along to be reviewed, and guess what..........?........it somehow magically finds its way into their system. It is hard to accurately gauge performance of review components when the reference changes capriciously.
A lot of folks who buy our stuff often want to know what kind of cables and stuff that we use here at the shop. Tell the truth, it has been in there so long, I forget what it is and where it came from. The point is that our system is stable. We know what it sounds like. We can evaluate our designs better than way, because we really do know how it sounds. It may or not be the most accurate, but it is repeatable. And that is key to doing any serious evaluation.
Pat