I had the ARC Ref3 with my V-cap/Bybee Spectron monoblocks and it was not a great match - very hard sound and a rising top end prominance.
I also tried my highly modded Sonic Frontiers Line 3 and that didn't have the sound I was looking for, despite the obvious excellence of the Spectrons.
I then tried the MBL 5011 and that was just great. I moved the demo to the MBL 6010D and decided to keep that. I can't actually say the 6010 sounds better than the 5011 as I never had them side by side, but the bigger 6010 is dynamic, quiet, textured and faithfull to the source and has clarity and the 'emotion' to draw me in to the music. I am set with this combo for some time and bear in mind I have been a tube man for over 20 years prior to this current set up! Nothing against tubes with Spectrons, but good SS gear is a proven formula in my set up.
My source is a Micro-Seiki SX-8000 air w/ Grandezza arm and Allnic Verity Z or ZYX UNIverse into Pathos Inthegroove or Aesthetix IO sig phono stages. Digital is Macbook and Kora Hermes DAC. Current speakers are Martin Logan Requests, soon to be compared with Apogee Scintillas.
Either MBL is a great choice and even though I have not tried it with Spectron, the Burmester preamps might be something to consider as well.