Thanks for you post. I still love my M3's and IMO at 92db 4ohm they are supremely easy to drive and sound wonderful. I'm driving mine with the Octave V70 Class A which is a little overkill but they are so transparent and dynamic it's really like I have the band in the room. I did have to do some room treatment and that is what I discovered the OB's prefer. I think your Aric should be able to power the Spatials and I've seen on the forums people using flea-watt tube amps to power them. They love tubes. Low end is deep, clear and tight. Mids are glorious and highs just so sweet. Clayton is actually producing a new speaker with his new company that I have heard great comments on. Depending on your budget I see the M and X Series come up for sale and maybe one of the X series with SET amps might suit your needs. Either way IMO you won't be disappointed with the Spatial line. X3's at 97db would be my next recommendation. Happy Listening and I appreciate you reaching out.
Rene