Mono Blocks / why are they not more prevalent? + Wyrded4Sound SX1000R

I also like tube monoblock amps.   I am currently running two McIntosh Mc275 amps in monoblock mode.  I believe you get more dynamic headroom, more current, better handling of low impedance drops of specific speakers (like my Wilson Watt Puppy 8).  Crosstalk is also nonexistant.  

Personally, I think the advantage of monoblocks are mostly effected by the architecture of the amps, the type of speakers you choose to use, and the size of the room. So, in my case, a large room, and tube amps with Speakers that dip to low impedance at specific frequencies is a good use case for monoblock tube amps.  So, in the right use case, I do believe you get better sound than the same monoblock amp in stereo mode. 

Seven of my last eight amplifiers have been monoblocks.  With their dedicated (not shared) power supply, monoblocks typically offer the advantages of superior channel separation without crosstalk, improved soundstaging, absence of inter-channel modulation, and increased dynamic headroom.  They also facilitate the use of short speaker cables, at the expense of longer ICs and PCs.  However, monoblocks using a bridged load design can be noiser and are certainly less effective (or even problematic) when driving low impedance speakers.

To your question, I have found monoblocks to be quite prevalent although the move to more compact systems (by some) would certainly benefit by the use of stereo amplifiers.  In addition, all things being somewhat equal, stereo amplifiers are less expensive (per watt of power) due to the absence of redundancy of expensive parts such as transformers and metal chassis.  Therefore, they may be an easier product for manufacturers to move.

@emergingsoul - I respectfully disagree that 'nobody likes to live in an apartment because of the noise'. I've lived in an apartment for 35 years and quite enjoy it, and there's a lot less unwanted noise between floors (in my case, none, unless nobody but quiet, non-vocal people who don't listen to music or watch TV have lived above or below me for 35 years) with a foot of concrete separating them than in any house I've lived in. 

I am not sure how much difference you will hear on the Wyred4Dound Sx1000R compared to the stereo version. 

But on audiophile level equipment the difference in sound quality is subtle but important. I lived with both two Audio Research Reference 160m and a Reference 160s for two years. The soundstage is bit wider and deeper and instruments therefore more separated on the monoblocks. The sonic characteristic are exactly the same.  However, the individual impact of the instruments is slightly less. I think that is because you still have the same power but spread over a smaller three dimensional space. I have heard from a number of other owners of high end amps that this is exactly the differences they had heard as well.

For me, the two monoblocks are superior to the stereo version... I think the difference in price tag was about $10K. Reflecting two cases and additional labor. Why more people don’t do it is the cost. 

So the trade off is what sonic quality can you get if you took the difference between the stereo version and the monoblock versions and just buy a better amp, Until you get pretty  high the answer is usually buy a better amp, 

"If you ever get far enough to get to this level you will have the fun of installing your own outlet because a licensed electrician will not install it. Does not conform with current electrical regulations. https://share.google/83rLotsqDXw5JYzaz"

Not necessarily, it depends on your electrician. When I had my 2 new 20 amp lines put in mine said he couldn't install my audiophile-grade outlets but then I showed them to him and he could tell that they were very high quality and not at all questionable so he went ahead and did it. Maybe against the rules I guess but seems perfectly fine to me.