Speakers for room size that provide greater detail.

lots of comments already

my 2 cents

-- wharfdale lintons are not resolving (nor engaging) at all... good for background music in my book, that is about it, not suitable for intent listening

-- better kefs proacs (one of my faves) joseph audio can be very good very resolving very engaging traditional box speakers, spendors are quite iffy, they can be all over the map, some expensive recent ones have sounded downright BAD to my ear

-- atcs and b&w and focals can be very very good or can be very very bad -- very finicky and hard to match and synergize unless you are quite experienced or have a damn good dealer... not for the faint of heart

-- once you do maggies right (proper setup, proper amps, subs) it is VERY hard to go back to a box speaker -- they are just more like the real thing, especially in a medium to large room

-- i have had quite bad luck with dynamic open baffle type speakers... tried several (spatials, lil songs, pure audios...) in every case i felt they sounded downright poor, yes they are dynamic and open but there are unseemly distortion artifacts that really bothered me, they don't image right -- i tried and tried and tried and they never sounded remotely correct 

your mileage may vary

There is a pair of Penaudio Ceyna on the other used audio mart site that has me interested but I am set with my current setup.  Fits your performance parameters and is a small footprint but noted for its SQ exceeding others in its price range.  Rarely do these come up for resale.  Good luck.

Martin Logan

Philharmonic BMR HT Towers—their resolution keeps up with $50K^ speakers. 

Friends had magnepans up to the 20.7. I never liked them as well as box speakers.  1 of my friends did sell his 20.7 to move to a box speaker.

i have revel speakers in a couple of systems. For your size of room, I would go for a used pair of revel salon 2’s. Much better than the usher md2, and dynaudio. 
Your rotel will be holding you back. When I had a room that was 27 x 16 x 15’ tall, I had the top of the line Classe monoblocks to power my Revels and large ushers.