Bigger sensors always offer bigger advantages. 135mm format is much larger than 35mm format. This will typically result in a lot more resolution and clarity when working with the files. Not to mention a lot more detail. Imagine a file of 60 MP's vs 18 MP's. I've noticed less grain/noise as well in a lot of MF files. A 20x24 print remains incredible in MF, while that size of print remains subjective on whether it's acceptable or not for 35mm format.
Thanks, thats good to know. If I ever get rich I'll look into getting a MF camera.
With both current and past technology everything in photography is a compromise from 'optimum', whether it be lenses or camera bodies. I used both MF and 35mm in film days when MF really was MF (6x7) and gave a substantial increase in 'IQ'. But the problem is you loose a huge amount of flexibility along with gaining huge cost implications. In the end I dropped MF and concentrated on optimum technique with 35mm.
My partner in Building Panoramics started his career assisting to a top name in London during the '80s, and bought himself a Bronica MF outfit. The (very successful) pro told him to forget it and concentrate on getting best results with 35mm.
Modern digital MF isn't that big and doesn't have the advantage film MF had over smaller formats, but the drawbacks remain the same. I know one portrait pro who uses Hassleblad. This pictures are impressive. Would they be any different if shot on a 5D with 85 1.2 ? I think not.
The issue of flexibility is one of the reasons I find APS dissatisfying: it's a substantially smaller format than FF, but generally offers nothing better in terms of flexibility or size. However there is a significant cost advantage.
Also you can emulate the feel of the larger format by stitching FF assuming your subjects not moving.
I would guess that digital MF is either a static or shrinking market so can't see Canon getting involved IMO.
(Just had to pop back in and change some errors in this post : must stop trying to type long posts on iphone whilst sat on loo )