I wasn’t very clear! I don’t want to keep the Marantz. I want a small decent unit that has a CD player (like the Quad) to replace it.
The speakers are most important as there is so much choice.
Does the Quad live up to the reviews that seem to rate it well?
My guess is that the Rogers can be improved upon as they are so old and many speakers will sound better?
I've just read a (2018) review of the Quad model you're interested in.
If you must have CD built in, then I reckon you'd have a job to do better.
As previously mentioned, the fact that your speakers are old doesn't necessarily make them worse than new ones - no doubt you could do better though.
With any new speakers you try, preferably with that Quad, give them a chance.
When you've become familiar with your old sound - genuinely better speakers can sound wrong at first. Don't write off anything that immediately sounds "too bright".
It can take a while to appreciate just how much better they might be.
In my opinion, brain 'burn in' is MUCH more of a thing than any other 'burn in' you might read about.