So far, most discussion has centered around the perceived build level..
But let's look some more at the finders. There's a world of difference between a 1:1 finder -as on the R3a- and a 0.6x finder. If you're into lenses in the 50mm range, the 0.6x finder isn't really the best match IMO. I found the 50mm framelines to occupy a fairly limited region of the HexarRF's total viewfinder. It goes downhill fast with anything longer. For wide lenses it's great however, and I could frame the 25mm without external finder no problem.
Another differentiator is the motorized film advance. You either love it or hate it. It's fast, but not anywhere near silent. On the plus side, it has a film leader out pause during rewind and a very accurate registering of frame advance, allowing you to swap films half-roll without any trouble.
I'd say first make up your mind about the finders, and motorized advance. These are things that affect the way you'll use the camera day after day. Then select the one that fits best..