Depends on your set-up. How wide/deep is your seating? Any limitations to ceiling placement?
The RSL uses smaller "woofers" and is angled 15%, so the sound distribution characteristics will be far superior to the 8" down-firing woofer in the JBL. The JBL will probably have superior low-end extension, however, any crossover to a sub will mitigate that advantage.
It's a VIRTUAL channel unless stated otherwise.