Just audited it somewhere yesterday night (Sorry, I need to keep secret at this moment)
With the inclusion of Denon Link 4th Edition with Clock Control (only AVC-A1HD and AVP-A1HD supports Denon Link 4th Edition), the soundstage is over 100% increase (Audited BD including Celine Dion BD, SpiderMan 3, Ip-Man, Planet Earth, Choi Kam)
The difference on separating 2 HDMI (Audio and Video) is not so big compare with Denon Link as Clock Control.
For audio part, since it embedded the main technology of Denon's top CD Player - DCD-SX (with 32 bit, 192k), the sound is very attractive. With true-balance output, I can say that it can KO my Meridian G08 (I also brought my G08 to Denon for comparison) (G08 is just 24 bit, 192k). Compared with Denon SA-1, DVD-A1UD is about 10% - 20% better!!!!!
We also have the comparison with Pioneer 09-FD. Without turning on the Denon Link 4th, the sound is 09-FD wins a little bit. But after turning on the Denon Link 4th, 09-FD......... Byebye........ Lost for 9 streets at least.....
For the picture quality, compared with 2500, 3800, 09-FD and A1UD, the result is
A1UD -> 09-FD -> 3800 -> 2500
In conclusion, for the end-user with AVC-A1HD or AVP-A1HD, having DVD-A1UD is a MUST! But for the user who does not have Denon's amp, keep your current BD player is not a bad choice.
Thanks for the report as you detail some of the comparison of which figures and numbers won't tell. At such price range, owner of A1UD definitely deserve a treat of this outstanding performance. I suspect even the price range did fall within the ~$20000 , the next issue would be as a non-AVC-A1HD nor AVP-A1HD's owner, is this worth the price by compromising the "non-functional" of Denon 4th-Link...?