I think it's really combo dependant cause, for my experience, i listened to a pair of mezzo utopia with Musical fidelity pre and power amp (can't remember the ref but top of the line anyway) with no result at all! The room was also very difficult to manage and we had to move the speakers several times inside the room to get a correct stereo image. Anyway the amps were pretty "MP3" kind of sound, not musical at all.
And you can't drive a B&W 802 with Naim! Not enought current, just watts for easy speakers. The 802 were probably the baddest speaker ever for small electronics with no juice. And even when you find big power amps, the sound still appear narrow.
One of my friend change is 802 for a pair of Usher audio BE-718. Even his child told hime that with the Ushers, it seemed that the players were in the room playing. The guy use McIntosh SS power amp and McIntosh tube pre and CD player.
It seems the new 800 serie is now driveable...
I'm quite surprise with your Onkyo reference? Depth is one thing but music is another matter! Onkyo is so colorfull and dull that even with more depth, i'm still choosing a Naim! (colored as well but fun)
Using an Audissey with Naim rather than Onkyo should give a better result. Using that kind of room correcting device during a show will certainly give a major asset to the system.
During the same audition with the MF and the Utopia, we used a Behringer room correcting device. It improved the overall sound but lost on the way all the music. It was synthetic like plastic!
It's important not to forget that we're listening to music, not just frequencies and spatial positionning.
Like i said, i'd rather choose a engaging sound, livelike and musical more than a perfect dimensional system with no life.
Anyway i appreciate your passion and your dedication to your customer Bo1972.