I did a long review of the Rovelight RT 601 here. I will leave that up in case it may be helpful for those who are interested in the light.
HOWEVER, I NO LONGER RECOMMEND THE ROVELIGHT RT 601 or 610 FOR ANY TYPE OF HAND HELD APPLICATION. This is because, the triggers the unit comes with (TR-Q6 or TR-612) override your power setting when set on the flash unit itself. And, there is no way to circumvent this.
I now only recommend the Rovelight RT 601 and 610 if you don't mind using your own trigger with it, or if you have no need at all to control the power from the actual flash unit itself.
To be honest, I still can't believe this, but the trigger seems to have been purposefully designed this way. It sort of makes you wonder why they even bothered with a power wheel on the light.
What I do still recommend for both hand held photography like I do are the original Rovelight 600B, the Xplor 600 unit, and the N-Flash.