What are the best GaN Amplifiers available today?

I’ve had the stereo Class D Audio GaN amp for the past week and it’s been great. Lots of detail but also very musical and engaging. Vocals sound natural and the soundstage has nice depth and width while separating instruments perfectly. Makes me wonder how the monoblocks would sound here.
 

I noticed things got better when I switched to a preamp with gain as the active but no gain Truth preamp had to be pushed to much. I have a little Topping A70 Pro that can be used as a separate preamp and when it was inserted everything really clicked into place. Very holographic and hearing much more into the music. 
 

Curious what other owners of the Class D Audio GaN amps are using for a preamp and how it works for them. And has anybody heard the stereo amp and monoblocks in your system with any added benefits to sound and staging?

This stereo amp for a $1k is a smoking deal. 

@t_ramey I own the Class D mono blocks. Running them with a VAC Renaissance MkV preAmp. 
I am wondering how many $$$ I’d have to spend for any meaningful sonic improvement. 
They have to be in any discussion regarding the best bang for buck amplifiers. 
@2psyop stopped by to hear the system and I think he thought they were worthy. 
If your DAC has a built in pre try it. You might be surprised. 
 

@t_ramey I use Schitt Freya which has passive and 2 active level modes.   I’ve used both gain levels with the Class D Audio amp depending on SPL needed. Have not tried the passive but the Class D amp has adjustable input gain jumper switch on the back. I use default setting but gain could be increased to better match passive mode in theory (have not tried,  active modes are top notch). Just be sure to securely set the input sensitivity jumper if you change it.  

I have the older stereo Class D Audio GaN amp and I use a Luxman CL-38 Uc tube preamp.