Mine doesn't seem to be film-brand picky, since I use Velvia 100, Ektar 100, HP5+, and FP4+ in my RF645 with no problems, but it did have a CLA last year by Tamron in New York. Tamron's CLA cost was fairly reasonable (around $140 IIRC, which included repair of the shutter release switch) but I did have to send it back once under the CLA warranty when they didn't get the infinity focus right the first time. It's worked great since then. Better hurry if you want a "factory" CLA, Tamron is officially dumping all Bronica support in October of this year, although there will hopefully still be a few places that will service them. Absolutely my favorite all time MF camera, I'm seriously considering selling a couple of cameras to scratch enough cash together to buy a backup RF645 this year.
I wish somebody like Cosina would copy the size (especially the feel of it in the hand and the control layout), and the outstanding VF/metering, and make a new version. I'd buy a new RF645 clone in a heartbeat!