I heard it side by side with a Nait 5i and CD5i when my dealer first started listening to it/evaluating it (it had been playing a few days to warm up). We couldn't tell the difference. What really surprised us was how good it was with internet radio. Most stations are pretty low bit rate mp3. They sounded very good. Not at the level of CD and Lossless music streamed, but far better than they had any right to sound in both our opinion.
Had I had the money for it and a need for a one box solution, I'd have bought without hesitating. Naim's better gear sounds better. The Nait XS and SuperNait are better sounding, but they don't do what the Uniti does. Different products for different needs.
If you like the Nait and really want the extra features, its easily worth its price. If you're after better sound than the Nait, look up the line. My only reason for hesitation with the all in ones is that sources evolve. In 15 years, you may have what would equate today as an 8-track receiver. The receiver still works, but the 8-track section is worthless. If you won't have it 15-20 years later, that's another story.