I sold my 400 to buy the 300 within the last 90 days. I also sold my SACD at the same time so this comparison may not be he best but here you go. SACD replaced by Krell Showcase DVD until new matching player for the 300 is released. Fit and finish on the 400 to me is better, just look at all four corners. The 300's focus seems to be on the front which looks great but the rest of the cabinet looks average. How does it sound? To me the 300 has more air about it and also has a wider soundstage. The 400 is a great int but sounded much harsher than the 300. Both systems ran Revel Salons and were connected using balance connections with Signal Cables. Did not have both amps at the same time so this is from memory but at this point I'm happy and have no buyers remorse. Hope this helps.
