I'm personally looking into getting an RFS and the research I have done thus far suggests it is an aggresive fish and territorial. Although I can't speak from experience, the reading I have done online suggests ways to reduce the severity of this by:
(1) Introduce the RFS last. Lets say by introducing the RFS 3 months later the other inhabitants have had the chance to claim their grounds. The RFS introduced later on will still be territorial, but will claim a much smaller ground compared to an entire tank if this was the first fish introduced to the tank.
(2) Provide hiding spots and a heavily planted tank.