My first med format was an RB67 PRo S, they are tanks. Built strong, and depending on the vintage have great lenses. Did you get a professional? Pro-S or the Pro SD body? What lens?
The thing that takes a bit to get used to is that the shutter is in the lens, not the body. The C lenses and the newer lenses are great. The original ones are hit or miss depending on the sample you get.
Got a link to the auction?