Well in my humble opinion Orbits system is quit good, it needs some tweaks though.
I think you should regenerate your ki slowly even when SSJ3 and when you are flying.
But maybe you mustn't move (or charge or anything) for some time to start regenerating ki slowly.
It would be like resting your character and he could have a hard breathing animation. It may happen that two chars regenerate in front of each other like in the show (I mean stop fighting for a while and talk) but that would take down the whole high speed gameplay. I
f you want to regen faster, you have to trans down, but what is with cell/buu/krillin??
Not bad that system, you can power up and down (to a certain level) depending on your skill difference, and someone with a high skill can power down to gain more PL (increase its max PL limit) and recharge ki faster
and if your skill is lower you power up but that will exhaust your character more.
And if you are SSJ3 your character can't hold this form forever as he loses Ki constantly, but he has a lot of ki so you can beamspam if you want (not that I appreciate it) or charge other large attacks, but if he does too often he has to trans down to regenerate.
Well, not bad after all. But it is a whole new system, changing the whole meaning of ESF, so maybe it could be implemented as a mod?!