New 2018 KEF R series...?

Did a little research. Looks like they borrow the baffle used in the REFERNCE series. They claim it's better. Here are the listed specs of the R3:

Design Three-way bass reflex
Drive Units Uni-Q Driver Array:
HF: 25mm (1in.) vented aluminium dome
MF: 125mm (5in.) aluminium cone
Bass Driver:
LF: 165mm (6.5in.) hybrid aluminium
Crossover frequency 400Hz, 2.9kHz
Frequency range (-6dB)
Typical in-room bass response (-6dB) 38Hz - 50kHz
30Hz
Frequency response (±3dB) 52Hz - 28kHz
Harmonic distorition (90dB, 1m) <0.3% 130Hz - 20kHz
Maximum output 110dB
Amplifier power (recommended) 15 - 180W
Nominal Impedance 8Ω (min.3.2Ω)
Sensitivity (2.83V/1m) 87dB
Weight * 13.5 kg (29.8 lbs.)
Dimension (H x W x D)
with terminal * 422.2 x 199.6 x 335.5 mm
(16.6 x 7.9 x 13.2 in.)
Finishes Black Gloss / White Gloss / Walnut

If you have freedom to move the speakers where you please then you can certainly find a spot the r7 will sound good. I think if there are any problems with placement and sound with the r700, you will have it with the r7. But 15x15 is big enough if you can make it a dedicated room.