I ran Axiom's A1400 with my 3808 acting as the pre/pro and the differences I heard were noticeable, especially when the volume was turned up. I was also able to notice a slight improvement in over all sound quality at lower volumes, especially bass notes. The question is did I notice enough improvement to buy the A1400? For me the answer is yes, even my wife said she would endorse such a purchase............... when I can justify spending that kind of money for a slight improvement in SQ, so this might happen when my kids are finished with schooling and the house is paid off etc. Do I feel I am missing out, not in the least. My 3808 on it's own sounds wonderful.
Just remember the Law of Diminishing returns, it is most appropriate when it comes to home theater/audio.