Resolution audio Opus 21 vs. CD55

Could anyone comment on their sonic difference?

I've listen to them both extensively and would be happy to comment on the similarities and differences privately if you want to email me.

I am a Resolution Audio dealer. I have never heard the CD55, but I do have a customer who replaced his CD55 with an Opus 21 after doing a head-to-head comparison of the two over the course of a week. If I remember correctly, his initial impression was that the Opus 21 had much-improved bass over the CD55...then later told me that the Opus 21 was much better overall; more sophistication and refinement, etc.

He originally contacted me via Audiogon, so perhaps he'll chime in...

I realize this is a old thread but I just picked up RA cd55. I plan on running it with a Hegel h1/Consonace c100b mk2 amp. I wad wandering if anyone could comment on sound? I only had entry level money so instead of buying a entry level piece from today i bought a hi end piece from yesteryear? I thought for &350. Bucks it was a better move??

Any inputs?