Could Class D really be that good?

I’ve really grown to like class d, and I’ve certainly noticed how different modules bring a differing palate of sound to your speakers. They can be neutral as heck, or, like the older ICEpower modules, have tons of slam. Having said that, has anyone tried to contact Red Dragon audio? I’ve sent the guy several emails, and no response. Are they going out of business? I was interested in one of their amps, because based on the reviews I’ve read, they seem to have the sound signature that I like from class d. 
Any info would be appreciated.

Let's get real. While the Fosi stuff is good, especially for the money, amps such as Technics SU-G700M2 at 10x the cost are 2-3x better.

I can't speak on the newer chip amps but I purchased a Hypex Nilai recently. To me it is a step above the Ucd & Ncore's I tried briefly in the past. I purchased the DIY model and feel it is a great amp for the money. Subjectively speaking of the class D modules i had tried in the past I found them to be a hair dry..touch analytical & 2 dimensional at times. For the low noise, transparency, power & size I still think the Ncore is a good amp.. especially when you consider the price. If I was still into Surround/Multi speaker movie systems I would be all about Hypex/Purifi modules. 

I tried an Elac Alchemy amplifier built around the older Ucd modules and felt that Class D amp was good for the money. Definitely better than just the basic older Ucd module but I still felt the top end wasn't as good as say a good class AB. Still a solid amp for the money in my opinion, I used a pair of them for almost a year. 

Anyway, the Nilai is definitely an improvement in my opinion. It's hard to describe an amplifier but I just find it smoother & groovier than D's I've tried in the past. I've only used it for a few weeks now but I can't find any faults in it. If Class D is able to improve upon this and keep it at these low costs I think that is a win for a lot of audiophiles. I definitely welcome more builders designing amplifiers around these new modules.. especially this Nilai.  

@atmasphere So if a class D has the same distortion signature as a good tube amp, it will sound like a good tube amp simply on that account.

Agreed. But I want to emphasize, with the low 2nd HD found in these Purifi / Hypex class D, you won’t be able to have distortion signature comparable to a tube amp and possibly produce the tube-like smooth sound. Let me give you an example of sound color signatures built in the Smsl Su-8. The 2nd, 3rd and other higher order spikes in the standard setting (upper left) are insignificant (-120dB, similar to Purifi / Hypex. Users could elect the "Tube 1-3" sound signatures to experience the emulated tube sound, where you could find the 2nd-order HD boosted to -90dB in Tube 1 (light) setting and -70dB in Tube 3 (strong) setting. That tells me the 2nd order HD needs to have high enough ’dominant’ spike (relative to 3rd & higher-order) to exhibit the tube-like smooth sound.

Here is the FFT plot for a real good tube amp, McIntosh 40, which confirms with the above. But, interestingly, Mc40 actually has slightly higher non-dominant 3rd hd.

Most agree that the 2nd harmonic is innocuous to the human ear; the real issue here is are the 2nd and 3rd able to mask higher ordered harmonics. I've heard the argument before that if they are 90dB down you aren't going to here them, which I think is false due to the fact that the ear uses higher ordered harmonics to sense sound pressure and it has over a 120dB range.

But if the 2nd or 3rd is masking them, then you have a 'tube amp' signature. The lower the distortion overall though, the more transparent the amp becomes.