NAD S500i is very smooth and buttery unique sounding player. This sound is created by their Class A biased analog output stage. This sound is great for easy, laid back type of listening. However I did not find the S-500 to be dynamic and resolving enough to my likings. It did not have the movement and pop in the music that others present. The high frequency extension was very mediocre against players in this price range. (I actually thought the C542 sounded more dynamic and resolving). Build quality on the S500 is nice and the transport had no problems reading any of my discs.
Though, I have extremely modified the S-500 and it can be taken to very far sonic levels once modified (power supply mods, new clocking, analog output stage removal, etc..etc..), embarrasing many higher priced flagships.
Thanks