I short time ago I had been auditioning several quality solid state amps in the 1-2K range in anticipation of making a purchase in a couple of months. After listening to the amps I asked to hear, the salesman recommended that I listen to the NAD S200, I almost said no thanks, but politely said sure. In a word "WOW". I hadn't listened to any NAD products in a while and was not expecting what I heard. Dead quiet, smooth, sweet, transparent, excellent dynamics and musical. If I was buying that day, the S200 is what I would have bought. Unfortunately, I wasn't ready to buy just yet. About a week later I found and bought a used one, and have had it in my system for about a month now and couldn't be happier. I truly believe this amp is an undiscovered gem!
Badwisdom, I don't know if your S300 will improve with time since the demo unit sounded fine and mine was already broken in. I can tell you that when I used the "normal" outputs (tone controls in) of my Adcom 565 preamp, the sound was slightly dark and veiled, but when I switched to the bypass mode (no tone controls) it sounded clean, clear and detailed.