Which Class D Amplifier? PS Audio, Ghent, Nord, Merrill or other???

Steve, always good to hear positive feedback from an actual owner

Tweak1: get those anti-vibration blocks that were cited in the Stereophile review. I got a box of 48 of them for about $26 and they are great!!! I put three of them under all of my components.

https://www.supplyhouse.com/DiversiTech-MP-2E-EVA-Anti-Vibration-Pad-2-x-2-x-7-8

jetter,

     The Stereophile reviewer heard significant sound quality improvements with separating the PS 700M monos and having them both on amp isolation stands rather than stacked.  
     I'd suggest just trying the amps both ways in your system and determine if you perceive the same significant improvements he mentions.
     If you do perceive large improvements, buy a couple good amp stands and locate the amps separated by placing one on each side of your rack on the floor or place one beside/behind each of your main speakers.  This would require longer inter-connects and shorter speaker wires but this shouldn't cause any issues with that.
     If you don't perceive large improvements, buy some sorbane pads or the blocks cited in the Stereophile review and stack 'em.
     I use thick maple amp stands (from Mapleshade) with conical brass spiked footers on my class D monos but I have room on the 6' wide top shelf of my rack with one at each end for a symmetrical look.  This works well but I never even thought of stacking them ( they're only about 7"w x5"h x 12"d) so I never compared stacked to separated.  
Tim

I recently had my Nuforce 9SE V3 amps upgraded by Bob Smith at TDSS to his Level 3. All I can say is WOW, I have a new stereo. I'm hearing details in the music that I previously didn't know were there. Although there is more detail, there is no harshness or edginess to the music. Bass slam is more dynamic yet articulate without sounding muddy. There is generally a more relaxed presentation of the music because of these attributes. Bob is a delight to work with and I highly recommend him.  Jeff

Jeff,

     Exactly, your description is what I hear listening to very good class D amps.  "There is generally a more relaxed presentation of the music because of these attributes" is an accurate summary of what to expect. 
    Besides the relaxed and seemingly effortless presentation, I would only add my perception that, due to their very high signal to noise levels and the resultant very low background noise levels, music seems to emerge from a dead-silent and inky black background that enhances the whole experience.
Tim