Hello Arupg,
I had a brand new Pass x350.5 amp hooked up to my Synergy 2i last week. It worked quite well. It had fabulous bass but the mids/highs were not as good as with the Pass Aleph P. Neither were the dynamics. It sounded a little more "laid back" because the Synergy has that characteristic.
I do miss the dynamics and "live" sound of the Pass x350.5 that my Krell FPB300cx doesn't quite deliver.
Depending on your speakers, room acoustics, and personal tastes, it might be a great combo.
If you are looking to wring the last ounce of "life" out of the music, use a Pass Labs pre-amp, as the Rolands just don't deliver the last word in dynamics.
I can't comment on the Coherence as I have not had one in my system.