If handheld is your only concern, then I would suggest you take a serious look at the Pentax 67 II as well. The Pentax is great for handholding, even if it is heavy. The handling is like an SLR, and the prism finder is easier to focus with than most MF cameras. I have a Mamiya AFD II system as well. It is excellent for most purposes, but I have two gripes about it. The first is that the light meter is not reliable at low light levels, i.e. for dusk seascapes and such. This may be only my copy, though. The other is that it is not in the same league of ruggedness as the Pentax. I do handprints up to 6x4.5, sometimes 6x6, but that is where my enlarger maxes out. To be very honest, the scans from 6x7 have a lot more detail because of the increased frame size. So my tendency is now to use the 6x7 for photos I want to scan (i.e. colour) and the 645 for black and white film to be printed. Occasionally I shoot slide film in the 645, though, and black and white in the Pentax. The lenses on both systems are really good, on the Pentax perhaps even slightly more so. They are certainly good enough for what mere mortals may want to do with them.
Originally Posted by abhishek@1985