I tried the upgrade this evening and it worked a treat!!!
Thanks to Digitalsurfer for sharing the firmware, Dex for hosting the firmware and to Beastie Boy for sharing the official installation instructions from Denon. It gave me more confidence to undertake the upgrade on my 3 week old 2910.
The difference in Version 8 over Version 4:-
(i) DVI output is now brighter and with higher contrast. Previously, DVI was noticably darker;
(ii) Green tint issue over DVI more or less resolved. This is still a tinge of green tint but easily overcome with the hue adjustment on the TV
(iii) consequently much better PQ over DVI!!
(iv) the DVD-A menu is now visible over DVI. It wasn't before the upgrade
(v) for SACD playback, the amount of noise is very much reduced at very high volume playback. No difference with DVD-A. Previously, noise levels was quite high at very high volume. I am talking about >85% levels here!
Overall, very pleased with the upgrade
. Will recommend those who have not upgraded to do so. The most difficult step in the process is to burn the file at ISO and Mode 1 and at the lowest speed. My software has a default of Juliet+UDF. To be doubly sure, I made sure that the CD-R was verified after burning.