It's included in the Maxon-subscription and pretty well integrated, so it's almost the logical move.
Anyway, I'd try out the demos for Redshift, Octane and VRay.
They are all quite similar. Redshift ist the fastest, but also a little barebones - like a racecar 🙂
Speed is crucial though - it allows for more iteration, earlier free time or higher quality (Depth of field, Subsurface Scattering, GI...) in the same time envelope.