Naim Supernait vs Nait XS vs Nait 5i: Differences


I have read that the Supernait sounds close to the XS. Are there substantial sound differences between these three models? What are the expected improvements going from the Nait 5i to the XS, and the XS going to the Supernait? Apart from the additional features of an on-board DAC in the Supernait, does the unit have superior sonics compared to the Nait XS?

Any advice would be appreciated.
ryder
Check here:

http://forums.naim-audio.com/eve/forums?a=search&reqWords=Nait+XS+vs+Supernait

http://forums.naim-audio.com/eve/forums?a=search&reqWords=Nait+5i+vs+Nait+XS
I compared the 5i to the supernait and would have to say sonically they are quite close but since the supernait has more power so it can 'control' low efficient speakers better. Then added the flatcap power supply and the power/control jumped up a hair more. The speakers we used were the Dynaudio C2's. For its price point the 5i held its own pretty good. With the xs and supernait you can add the flatcap where with the 5i you can't.
Thanks all for your comments. Tried to access the Naim forum but membership still pending approval. Guess my application may have been rejected.
To paraphrase Groucho: I wouldn't join any forun that would take someone like me as a member.