If you intend on shooting for commercial jobs, almost all art directors require digital files on set. They're used to seeing the images come up on screen and participating in the process of evaluating what's being shot. I don't know a single client who would allow me to shoot on film. Like others have said - shooting personal work is not an issue, but for clients, they're going to want digital.
Flatbed scanning 4x5 is more successful than medium format because of the thinness of the medium format film base. Flatness is a huge factor with that thin base (it was a huge factor for analog enlarging, too). You will want to pursue some kind of glass carrier solution with medium format on a flatbed, and those have their own pros and cons. Or go to a drum or tension-type scanner.
IIRC, Jobo was set to come out with a brand new processor. There are a lot of photographers buying their own scanners like the Fuji Frontier because processing and scanning at a lab is outrageously expensive. I scan using a Nikon 9000 and it honestly drives me nuts scanning a job. However, the results are absolutely amazing.
As others here have mentioned, shooting medium format film is an entirely different experience than shooting 35mm film. It is far slower and more deliberate. I am a former wedding photographer (1980s-1990s). I used mostly Hasselblad 500C/M, which has a manual film advance that required a full circle turn of the film advance. The medium format lenses are much larger and heavier than anything that you are used to. This also applies to the excellent Mamiya RZ systems, which are even heavier than the Hasselblads and Bronicas. There is no question that medium format will require a slower workflow. If you are used to shooting hundreds of frames per minute in a studio setting, that number will likely be reduced to 20 to 30 per minute with a medium format film system, even with an autowinder. Remember that autowinders on a 6x6 or 6x7cm format have to move a lot more film per frame and to do so safely and consistently is a much slower process than a Nikon F Series with winder.
My advice is that if you are looking for a much higher resolution system that will actually be enjoyable to use in a fast-moving studio setting, move up to a D800, which has a resolution that rivals today's medium format DSLRs. I have two of these. They are much lighter weight and ergonomic to use than medium format cameras of any type. Further, Nikon F lenses cost far less than comparable medium format lenses. You should also consider that within another 5 years or so, the average pro DSLR will have higher resolution than today's medium format DSLRs, so to move to medium format now may not be your best move.
I have went medium format digital and I have pretty much left it except for my Cambo wide and a few backs. Other than architecture and landscapes I hate it now, for those purposes it is great for the rest it slows me down. I have went back to shooting Canon and mostly on a 5DMarkII which I love. I also had a complete RZ system for a while and did not care for it with digital backs.
I was raised and trained on film and for a long time after switching over to digital, the film gear sat in the closet unused and the film stacked in the fridge.
Sometime last year I promised to start shooting more film again; it just has something about it that looks better than digital, IMHO. I love getting back into the "zone" that I used to get into when shooting film.
If you can get an RZ for cheap (I used to have an RB67 before switching to Hasselblad - that thing was a TANK of a camera) definitely pick one up and start playing with it. Pick up some cheap 120 b&w rolls and start learning the habits of the camera. I've been using my Hassy as a weekend "general" camera to have on me, and I try to break it out at the end of sessions with clients and just grab a roll or two.
Someday I'd like to pick up a digital back for the Hasselblad, simply because I've never loved using a camera more than it. Just the *KA-SLAP!* it makes is music to my ears.
