C41 is C41 and RA4 is RA4. (no I'm not gone mad)
So whether it is a minilab or a pro-lab, it all comes down doing the job correctly. The C41 processor is just a machine that automates the film processing.
BUT as with all things the devil is in the detail. Control strips, rep pump output, filter change, etc, it all comes down to good housekeeping.
And likewise with RA4 printing. I have printed optically and with scanned negs (Frontier & Pakon) and again it's the detail.
A pro-lab can charge more and be more attentive to their customer demands, but if they have sloppy practices then it is no good.
Likewise a minilab can be at the lower price range but be scrupulous in their processing and printing.
Colour balance can be a subjective thing. I have set an optical minilab printer to the correct print bullseye (technically correct colour balance) but the prints didn't look just right to me, and making a slight colour correction and I was happy.
Lab scanners I find are easier to use and keep calibrated. BUT just like going into a television shop and viewing all the screens on display, showing the same program (image) and seeing the difference in colour between each one, colour balance can be a personal thing.
Back in the 1990's some professionals (including myself) used my minilab for film work. We used to keep a referance chart for each of the pros with a colour balance correction, because we knew that's the way they wanted their prints.