It's too bad you are not fond of the 6x7 format, because for ultimate portability, the Plaubel Makina 67 or 670 is unbeatable.
I have recently traveled with the Mamiya 7II and two lenses, and a few other times with my Plaubel Makina 670. I definitely preferred the experience with the Plaubel Makina. Here are a few "real life" reasons why:
- When the Plaubel Makina's lens is folded in, it's very compact, and especially the fact that it is very flat makes it much easier to move around, hike, or even climb rocks. The Mamiya lens sticks out quite a bit and wobbles around when walking fast or climbing.
- I had problems with the Mamiya 7II's battery, I am not sure if it was empty or if there was a loose contact. However, a second battery would most likely have solved this problem.
- Dealing with two lenses on the Mamiya was a bit cumbersome... it can slow you down quite a bit, which was e.g. a problem when I was on a guided tour and not allowed to stay behind to take pictures.
- The Plaubel Makina is flat enough to fit into hotel safes. To me, this is a plus. In the last hotel I stayed in, I could not fit the Mamiya, while I am sure the Plaubel would have fit.
- The Plaubel does have a built-in light meter, which needs to be activated by pressing a button. However, it works happily without it, while the Mamiya doesn't. And as I have just learned, it will happen that you forget to bring a spare battery and cannot find a store selling one.
- The Plaubel has a 80mm f/2.8 lens, which will give you an advantage in low light, while the Mamiya's 80mm lens is a f/4.
- Metering with the Plaubel is straight forward and simple. I guestimate the shutter speed and aperture, check by pressing the light-meter button, and then adjust to get a green light. Over- or underexposing is then just a matter of slightly adjusting aperture or shutter speed. No further buttons to mess with... I like it that way.
Comparing Mamiya 7II to Plaubel Makina 670 slides, I do notice that the Mamiya's lenses are a bit sharper, and "clearer" in image quality compared to the Plaubel. The difference is barely noticeable though, especially the sharpness difference can only be noticed when doing "pixel peeping".
Well, that's just my two cents... after my recent experiences traveling with these two, I have seriously considered trading the Mamiya 7II for a Plaubel Makina W67 (the wide-angle version), and travelling armed with two Plaubels... one on each shoulder...