The Bronica RF645 is my favorite camera of all time! (Don't tell my Mamiya 6 I said that!) I've been talking up this camera on here for years. I am surprised that there is not more discussion about it. I have two bodies. One a very early SN. I also have the 45, 65, and 100mm lenses. I mostly carry the camera with the 65 and 45 lenses. I can do most of my work with just these two lenses. I got a really good deal on the 100 a few years back that I couldn't pass up so I bought it, but don't find anything too particularly exciting about it. It's not near as good as the 150 for my Mamiya 6. The RF645 is super lightweight, very ergonomic, and it's got just the right amount of bells and whistles. The automatic curtain when changing lenses is super nice. I take it for granted until I use my Mamiya 6 and have to remember to pull the curtain before lens change then remember to open it after! The meter on the RF645 is fantastic!! Dead on all the time. I can trust it, unlike my Mamiya 6.
I highly recommend this camera to anyone who wants a lightweight MF rangefinder.