Would this be an upgrade?

SONY DVP 9000ES even as SACD player is inferior to 7 years old ARCAM CD player (long time ago I have tried this CD Player Arcam Alpha 6 with some Theta DAC - do not recall which one, and it was far beyond reach of SONY) not surprising if Arcam alone was better/equal then SACD, more details you can read here:

http://forum.audiogon.com/cgi-bin/fr.pl?ddgtl&1046465483&read&3&4&

I have used both old Arcam 6 and Sony with supplied power cables. You said that SONY 9000ES as SACD could be better only by >6k$ others SACD player. Unfortunately this is not me and my wife heard, it was better by 300GBP 7 years player. I was so disappointed that I'm going to invest money in better CD (Wadia/Naim ???) not interested in SACD any more at least not from SONY for time being.
And I do not think so that Arcam is that good, I think that SONY is much overrated. I had for a few months P1/P3 it was big improvement with Arcam (totally different league them SACD SONY), but it was causing so much interference with AV-equipment so I have sold it. Perpetual Technologies units are poorly screened. Bought SONY with big expectations and was shocked how big downgrade it was to ARCAM+P1+P3+PowerSuply.

Sorry this is just what I heard. I'm not impressed at all and I personally do not believe that any tweak will make this SACD player contender to high quality CD Player. Of course my personal opinion, by any means I'm not a guru here.