I own both.
I use the rotor for 3 reasons.
1) easier to clean if theres a break inside
2) less things to have to worry about, you dont need to change the mic level, or worry about stack monitoring etc
3) on / off. done.
Although,
the rotor is;
heavier,
has a more vertical feed position (pod has to be ontop of the hopper)
The prophecy does have great points, Its easy to strip but not as completely as the rotor, the rotor is very quick but the prophecy is completely tool-less. Its got a better capacity, and good battery life. If you get on well with settings and fiddly bits, the prophecys a great loader. and it sits really really low.
The rotor is very quick to completely strip, down to the motor like. very consistant and very hard to break. Little can go wrong with one. The battery life is AMAZING, changed my batterys once. In 9 months playing with one..
Basically
if you like fiddling, a prophecy will suit you
if you like taking something out your bag, putting it on a marker and going the rotors the job.