Sony SCD-1 vs SCD-777ES, AB sound differ

After researching the two units the SDC-1 has potted transformers, five feed vs four, and balanced output. From the internal pictures I have seen the fixed pick-up mechanism looks different also. All things being equal (RCA output used, breakin time), how do the two units differ in sound? I have heard the SCD-777ES is dark sounding as compared to the SCD-1, more forgiving, clearly not as good, and not worth the cost savings. My thought was to use the $1100 cost savings to feed the SCD-777ES with pure AC from the PSAudio P300. Any input from someone who has AB the two units please suubmit a follow-up. I am planning on going direclty into a McCormack DNA2 using EVS nude attenuators, Harmonic Tech cables, Thiel CS2.3 spk.
If your gear allows the use of xlr in/out then go for the SCD1. I never had a chance to a/b both side by side but I did first listen to the 777ES at a local Goodguys store in the Bay area but ended up purchasing the SCD1 myself. When a/b between RCA and xlr on my SCD1, Well I am glad I made the right choice. XLR somehow always gives the best sonic performance. The rest of my gears are SimAudio Moon P5/W5 that drives a apir of Gershman Avant Garde with JPS Superconductor 2 balanced cables. PS300 as my power plant. Good luck!
Thanks for your input Audiopho. Can you elabrate on the differences between XLR and RCA out of the SCD1? Was a pure AB test made? My amp has both input types. Was the P300 powerlink a good investment? How did it improve your system? What power factor works best? Thanks.