I have a C368 in my girlfriend’s system and like it, but 80 Watts is 80 Watts. We got a HUGE sound quality boost by piping its pre-outs into a Parasound A23 (Tannoy Eyris DC3 speakers, 89 dB/ Watt). The C368’s preamp and DAC sound great, though. And we have the BlueOS MDC module (the older one) but haven’t been impressed there. We can only get it to show / connect once in a blue moon, with no rhyme or reason why. We had to fall back to bluetooth (which worked very reliably, at a slight ding to sound quality) until I bought a Node 2i. The Node 2i is much more reliable; I’d guess & hope the newer BlueOS MDC module would yield at least as much improvement. But it’s still not perfect, and perhaps not quite good enough to satisfy me in the long run. I may end up looking for alternatives.
I agree you’d be better served with a C 658 into a beefier amp. I wish I'd gone that route, now.