Power supplies with readouts won't give speed in CPS for most rotaries due to the lack of "On/Off cycles per second" (Hope I'm explaining that correctly). Many issues arise though, when (like with the Eikon 300), the duty cycle exceeds 99% and the supply turns itself off, which is supposed to be a safety measure with coils from what I recall. There are a few machines out there here and there that give one sort of reading or another, but I find that with a rotary, the best test of speed is to do some whip shading:

If you get "Train Tracks", it's running very slow for your hand speed
If you get "Peppery Dots", it may still be a little slow, but you're right around the sweet spot
If you get "Parallel Lines", it may be running a little fast for your hand speed

This works great if you are using a new rotary for the first time, and are unsure of the voltage 'sweet spot' or if you are running a power supply with out a voltage display.