I can’t comment on the McIntosh D150 but I own McIntosh MC462 and have had a number of Rotel amps over the years (still use them for surrounds in my theater).
Anyway run what sounds good to you. McIntosh does not really come into it’s own until you get into their high power amps with autoformers. That is where you get into the McIntosh sounds.
McIntosh often outsources their internal DAC to other brands. Probably just a sabra chip found in many other brands. Their theater processors are made by Marantz then they use their own input and output stages.
anyway McIntosh is fine (I own them so no hate) but it is over priced on the lower end. I find the C53 preamp and MC462 and higher amps very good but again lots of stuff cheaper just as good.
now in truth I would run what you have and change your speakers. Your speakers are simply bright and forward. I have owned the 703s which is very much like your cm9 and I am 100% sure they are the bottle neck in your system. Very uneven respond and will be setup critical as they have a number of issues.