The thing is, whichever you choose, they will both feed paint brilliantly, and keep up with any marker.
I use a spire and cant fault it at all, as said above, it does hold a true 200 paintballs, so slightly more than a standard rotor, also the opening is bigger which makes feeding paint quickly easier.
You will never know if it has had a jam because it clears it on its own.
The rotor does have lots of funky designs though, if thats your thing.