rotors are a shedload of money, but for good reason. they feed plenty fast but their best feature is how quick and easily they can be broken down to clean out incase of any breaks and the battery life is brilliant just as cowface said.
however a very strong contestor is the empire prophecy. i personally prefer it because it is sound activated (in my experience i have broke a lot less paint in my prophecy than my rotor) and holds ALOT more paint as standard than the rotor, the advantage being the prophecy has the same small front profile as a rotor.
another great advantage is that changing from lid to speedfeed is very fast and doesnt require changing an entire shell the same as the rotor. when you weigh it up its £90 for a prophecy and £20 for the speedfeed. whereas a rotor is £130 and £35 for a topshell and speedfeed. and if im being brutally honest the standard dye speedfeed is one of the worst out there.
prophecy is a little more complicated but doesnt take long to master, and is a hell of a lot cheaper. and to be honest, in my personal experience again i have had maybe 1 or 2 jams in my prophecy as opposed to the rotor which has jammed on me on considerably more occasions.