I changed from Mamiya 645 to the Mamiya 6, then Mamiya 7, because of the difficulty in handling the brick-shaped 645 out in the hills. The Mamiya 7 is very portable, easy to use and the lenses are top quality. If you look at ebay they hold their value well too. For close-up work there can be a problem with parallax since you look through a viewing window NOT through the lens. For macro and close-up work the 645 is better, for travel, landscape and city shots the Mamiya 7 can’t be beaten for what I do. For colour work there is a special polariser that you can set before pushing it down into place. You would have trouble using graduated filters though since you don’t look through the lens so you would need to guess how far to push the filter down in front of the lens. The 7-II is better than the mark 1 if you want to use the multi-exposure lever. Otherwise the mark 1 is the same except for a few cosmetic changes (strap lugs, cable release socket moved, lens change lever different).