I've been running 4 R-14S speakers as my Atmos for about a year now. They sound great IMO, although they crossover at 110.
Tip: If you have audessey, get the app. Somehow it calibrates much better with the app.
Home Theater Setup
Receiver: Denon X-3600H
Amplifiers (x2): Crown XLS1502
Main Speakers: RP-280F
Center Channel: RP-504C
Surround Channels: RP-250S
Rear Channels: RP-600M
Height Channels (x4): R-14S
Just my 2cents
Parker