Your downsizing is still bigger than my present situation and I have Tonian floor standers with no problems I can detect due to listening in the near field. My room, aside from dimensions, is similar to yours. I think you'll end up about 9' or so from your speakers so I'd position them at least 10' apart (try more if you can) and you should be pleasantly surprised.
I had to get rid of my Legacy Classics due to bass overload but I didn't need to go with monitors, just something with less bass as the room more than made up for it.
All the best,
Nonoise
I had to get rid of my Legacy Classics due to bass overload but I didn't need to go with monitors, just something with less bass as the room more than made up for it.
All the best,
Nonoise