Sergio Ortega , Jun 19, 2006; 05:32 p.m.
You should post this question on the Medium Format site...you'll receive literally dozens of responses there. Also if you do a search on this topic there you will turn up hundreds of threads discussing the pros and cons of both cameras. I've owned both of these cameras: the Fuji 6x9/65mm and Fuji 6x7/90mm, and the Mamiya 7 II/65mm, though not the 43mm or the 150mm lens. Some thoughts...
The Fuji will be much, much cheaper. It is totally manual, uses no batteries and has no metering system. You're limited to one lens, but the GSW 6x9's Fuji 65mm produces outstanding images, equal to a 28mm lens on the 35mm format, with the same aspect ratio. It's a great choice for general landscape work.
The Fuji is not as compact or as finely made as the Mamiya 7, it's a bit crude in general feel and operation, but it's a very rugged camera. It's not particularly heavy, but it is a large camera, so if size is a major concern the Mamiya 7II would pack in a smaller space. There are some issues with the design of the Fuji's shutter that limit use of shutter speeds slower than one second, but it can be done with a little creativity. Using polarizing and graduated ND filters with either the Fuji or Mamiya can be a real challenge, but that's a problem with all rangefinder designs. Overall, the Fuji is a great camera, but with some limitations.
The Mamiya 7II is a great camera as well, the lenses are also outstanding, particularly the wide angle designs. The bodies and the lenses are quite expensive, especially the 43mm. I use the 65mm lens, which I find the most useful focal length for me, and it produces great images. I'd like to get the 43mm, but I cannot justify the prices. The metering system works well for me with the 65mm lens. The aperture priority exposure mode with exposure lock is also very useful for fast street photography and any type of work where you have to work quickly.
I have not read any reviews mentioning focusing difficulties with the WA lenses, specifically the 43mm, rather there are problems reported with accurate focusing with the longer lenses, a common issue with rangefinder designs.
I sold the Fuji cameras so I could get the Mamiya 7II/65mm. I don't regret it, as I prefer the Mamiya 7II overall, particularly for handheld work. Good luck with your choice.