Do Spendor A6Rs bringing out the best of my system

My system consists of a 282 with SuperCap DR and a 250DR.

For Digital music I have a NAC plus XPS DR with a CDX2 plugged into the DAC and Unite Serve on trial while I wait to try the Core. I have a Lenovo IX2 in a RAID 1 configuration (mirror).

For vinyl I have a Rega RP10/Aphelion/Aria (phono stage).

Its all mounted in 'HiFi Racks' with 400mm between the power stuff and the sources.

I have a dedicated spur using shielded 4mm cable to a block of 4 unswitched Crabtree sockets.

i have 6m Chord Odessey 2 speaker cable, Rega interconnects on the vinyl and Chord for digital.

Our lounge is 7m x 5m x 2.3m, with large fireplace and lots of doors (including wide pair to dining room and to hall) and windows. Speakers are positioned on the outside long wall next to the patio door. Not ideal so good speakers may help.

HISTORY

Xmas 2015 I bought a Uniti 2 and the Spendor A6Rs, a combination which sounded good in the show room with the RP8. Perhaps because I used Powerline without being informed of the issues, the system never sounded that good at home despite being played constantly to run it in. Cutting the Powerline story short, I bought a 10m cat 5e style modem cable (its bending radius is much better than Cat 6/7 Ethernet cable) to move the BT Hub 5 to the lounge where my system is and a TP Link wireless range extender to reach the parts that could not be reached. It is essential not to introduce complexity into a home network to make the Apps work without the Streamer disappearing from time to time. So follow the advice in the Core literature and connect direct to your hub. I didn't ever used expensive Ethernet cable, but if the Core is really good I may.

The system did not start sounding good (I got sold on separates when I heard the amazing difference a well run in SuperCap made to my 282) until just before Xmas 2016. This somewhat suggests that demos to compare various boxes need to be done with kit from your dealer that is known to be fully run in, and then it takes a week for it to warm up and you have to return it! To be quite honest I did not like Digital music from the CD player until December 2016, and now it blows me over if I stay up late when the mains is quiet, but I still like vinyl at its best. What I also realised in December was that the CDX2 is much better than the Unite Serve through the same DAC. The detail comes out that gives the music life. It's also not surprising that the hard disk inside the US and the external DC converter are its SQ weak points.

I'm quite interested to understand why with heavy use it took so long to produce the NAIM sound.

My question is: 

Do the Spendor A6Rs do my system justice? If not which speakers would suite it best?

Generally the next best seems to be the Spendor D7 which suite the relatively low power of the 250DR. The PMCs Twenty 26 seem to require more oomph at 86db sensitivity and similarly the Fact.12 (84db) although there are some suggestions that it and the Fact.8 are good. One recent thread went for the PMC MB2 SE which has a sensitivity of 91db which means it should be as easy to drive as the A6R with a 250DR. Does the Preamp power supply assist driving the speakers as well? The MB2 would have to be sensational to justify the price, but on the other hand I don't like constant upgrades as it seems expensive in the long term.

Looking forward to your thoughts. Thanks for reading this far as well.