True Blue:
Heard them with Naim Nait 5i + CD5i, Naim Nait 5i + Rega Apollo, Naim Nait 5i + Rega Saturn, Rega Brio 3 + all aforementioned CDP's
I heard the Rega RS3's with Nait 5i + CD5i, Nait XS + CD5X, Arcam Solo-Mini. Ironically this is what decided me upon getting the Nait 5i/CD5i instead of upgrading my speakers from R3 to RS3. No reflection at all on the qualities of the RS3's (they are superb) it's just that the upgrade from Solo-Mini to Naim was so profound that it outweighed getting better speakers and I could not afford to get the Naim kit and the RS3's.
(That was a very expensive 'speaker upgrade' for me considering I never ended up with them!)
I have also heard Rega RS1's with Nait XS + CD5X (and possibly Flatcap 2 though I did not ask at the time if it was connected because it was brilliant enough already!)