It also depends on what you call rig management and what features are needed.
For OC stuff, Afterburner is free, and miners allow this in the batch file
For remote access I personnaly use Chrome remote desktop extension which is free too, I don't need to go physically to my rigs location.

And the pool interface and miner interface gives me enough info about rigs status performance etc...

I don't really feel that I need anything else.
I've tried HiveOs and went back to Windows... but of course this is a matter of taste which certainly has already been highly discussed somewhere else.

What do you think is the most important for the rig management ?

Perhaps it is easier to switch the mined coin ?