Hi John, glad to hear you like the improvement coming from Opus cables. My Ref MM2 cables are a big improvement over XL and I imagine Opus should have at least similar or even more improvement over MM.
Btw, I heard Transparent soon renewing all of its cable lines, completely changing current MM2 topology to a new one, bringing a higher line over Opus which is hard to believe given its cost and performance. Personally, I am so pleased with my Ref MM2, no intention to consider any upgrades within 4-5 years.