I use the Plaubel Makina 67. A rugged camera with a top notch Nikon lens. Bright viewfinder. The mass of the camera allows for steady hand held shots. In that regard, easier to control than my Fuji GF 670. My other folder is a Super Ikonta B. I like the 67 format. With Makina and Fuji I shoot slides. I would say that all depends upon your preference: 66 or 67. If you already have a 66 camera, why not try 67?
Of course, the SI B will outlive me.Have owned it for 50 yrs. Bought used at Olden. Anybody remember Olden Camera in NYC?