I currently have a Rega Brio-R that I have bought out of curiosity. I used to own a Naim integrated years ago.
The Naim amps are much better. The Rega has a kind of likeable enthusiasm and a fast, almost aggressive sound, but is tonally a bit dull and unrefined. The Naim is a much more balanced, refined sound (by comparison). I would not hesitate to choose the Naim out of those two.
But you should also try to hear the Exposure 3010 s2, which is better than both.
The Naim amps are much better. The Rega has a kind of likeable enthusiasm and a fast, almost aggressive sound, but is tonally a bit dull and unrefined. The Naim is a much more balanced, refined sound (by comparison). I would not hesitate to choose the Naim out of those two.
But you should also try to hear the Exposure 3010 s2, which is better than both.