I have a Friend and client (Shaukat) who lives in Simi Valley (maybe 30-40 miles from me)
Several weeks ago he visited my house and listened to my two RM40 systems (both 2 channel and HT)
I have both the Son of AMPZILLA (one of B's favorites) and the NuFORCE Ref 9 v2's, since I am a dealer for both.
Shaukat was "impressed" with his audition of both here in my room, but as many who have visited might say, my room IS NOT a typical listening space.
The 2 Channel System is HIGHLY damped sonically and is very pure (as in little reflected sound) sonically.
The HT is a bit more conventional, but still it will not tell you what a component will sound like in YOUR Room.
So we made plans for me to bring my Preamp (Bryston BP26DA) and the SOA and the Ref 9 v2's, as well as the same cables (higher level AudioQuest) to A/B in his room with his speakers.
First we played several ref cuts through his present system which consisted of the TOP Yamaha Receiver through a 600wpc CineNova.
Frankly it sound way better than it should have.
Josh Groban, Bela Fleck and the Flecktones, Santana, Nils Loghgran (sp) and several other cuts we both were familiar with that had lots of elements from which to form sonic opinions.
First up we ran used the following:
Denon 3800 DVD player (as a transport)
AudioQuest Digital Cable to:
Bryston DAC in the BP26 Preamp
Using AudioQuest Cheetahs (XLR) cables from the Bryston to:
NuForce Reference 9 v2 monoblocs through:
AudioQuest Pikes Peak Speaker Cables to
VMPS BCSE RM40's
Of particular interest was a "peak" Groban hits in one of his cuts that almost all systems distort. CRYSTAL!!! I mean no distortion and crystal clarity.
The NuForce had gobs of good quality and highly detailed bass as evidenced in the Bela Fleck cut on their live double album of Amazing Grace. Such depth clarity, attack, detail and tone is hard to live without once you have heard it and we both have heard it

Even at high volumes we heard realistic power, detail tone, soundstage and imaging.
Shaukat's listening position is probably 3-4 feet further from the speakers than mine, and the difference was you heard a larger venue, and performers farther away as in maybe 7th Row Center, rather than "Front Row" Center. It sounded great.
So we unplugged the preamp from the NuFORCE, and switched the XLRs and Speaker connections over to the SON of AMPZILLA

We had already had the SOA plugged in a bit so as to warm it up.
Back through the Ref cuts again. Again Josh Groban had NO distortion at all, only purity to his voice, and the Bass and details to it were there.
The primary difference we heard was in "smoothness and tonal quality".
The SOA had a tubelike smoothness, which should not be taken as a "Softness" since it was not muffled or lower in detail, but it just didn't have the "edge" of the NuFORCE.
Bass was equally as detailed but "ever so slightly" not as forcefull as the NuFORCE.
Midrange was silky and rich, but again, this did not take away from the details.
Soundstage and imaging was superb, just like the Ref 9 v2's.
Then we switched back to the NuFORCE to confirm the differences, and it pretty much ended up boiling down to preferences.
The NuFORCE had very deep, and impactful bass. It was also highly detailed and maybe this caused it to be a bit more forward. The detail "did not" cause it to be strident, or harsh.
It readily hit hard with high energy transients and dynamics, and produced no listener fatigue (I think we could have listended for hours).
The SON of AMPZILLA was the Rich Tone king, and had deep and quality bass and highs, but balanced in a way that made you think tubes on steroids

No losers in this shootout since both amps did sound wonderful (or else I wouldn't offer them) but it was more of two great choices.
Poor Shaukat, thought that this type of audition would make it easier to make a decision. No such luck.
Now he has to figure out which amp he can (or can't) live without. I find myself switching "back and forth" every so often, and can't decide which one I like best either.
They are very different, but also both are very good at what they do, and that is produce some incredible music through B's VMPS Speakers.