Upgrade to McIntosh

I don’t think you can go wrong.

1. Room size - take into consideration. Could the C8 + MC275 maybe be more than you need?

2. I have not heard your Sonus bookshelf speakers but do they need that much (C8 + MC275) to drive them?

3. I have the McIntosh MA352 (driving Revel F328Be speakers) and have never been happier. While I might change other components, the MA352 & Revels are the last amp / speaker setup.

Good luck!

@wolfgangamadeusaudiophiliac Admittedly it is hard to answer your question re. the Revel F328Be (I initially owned the F228Be but after about a year, upgraded to the F328Be).

I have a smallish room 13’ x 13’, well treated with panels, diffusers, and small bass traps. Additionally, custom length bluejean speaker cables, after market power cord, dedicated power to my room, power conditioner... The F228Be bass port is in front; the F328Be in the rear. You can surmise the rationale. Interestingly, (using the Wilson placement process AKA the mirror reflection) I’ve found I have to be closer to the "center" to have optimum sound stage. 99% most likely my room, not the speakers. Imaging is incredible. At times, I hear the drums "on my right knee" and others there is no L or R depending on the music source/recording, etc. Re. your questions of euphonic / dynamics, all I can say is that the power match with the MA352 (integrated / tubes) creates a wonderful warm presence. I hear things I've never heard with these speakers. Fine nuances, Goldberg "humming" as he plays, the singer's breath... I mean at times, it seems better than if I'd been in a symphony hall. Bottom line, these are my last speakers and will likely move homes in the next few years hoping to have a bit larger listening room. As I noted, these and the MA352 are my anchors. I may upgrade other components, but not the amp or speakers. Sure, there are better options but for my budget and enjoyment, I could not be happier. BTW, shop around. The Revels weigh in around $16-17K for the pair but you can find sources that are closer to $10K if you’re patient.

Good luck and as Hans says, whatever you do, enjoy the music.