Interesting you point that out because I see less difference from MF. I have one 6x9cm printed to 11x14in where I feel like I can see branches on the trees at the skyline, which is one of the looks that appeals to me, that I get from 4x5in... Which is to say that 6x9cm approaches 4x5in in that respect.
I actually very much like 6x9 and have a lot of 6x9 negatives, but I'm still trying to figure out how best to print them. I find traditional print sizes tend to crop off too much of the scene, but printing them proportionally with no cropping makes them difficult and more expensive to frame. I think some of my best shots are on 6x9 though.
A 10" X 8" contact or print will show wonderful detail, but if the content is boring or rubbish, it can never compete with a 35mm print of great composition, context and timing.
when it comes to resolution and sharpness. I don't think it improves a photograph; it is nod a 'nice to have' in my world. In fact I'm almost entirely neutral to it, to the point where it doesn't really register.
At the same time, I appreciate a really well printed photograph, and in my darkroom I always strive for making the very best print that I can make. But that never has anything to do with resolution. Ever.
I actually very much like 6x9 and have a lot of 6x9 negatives, but I'm still trying to figure out how best to print them. I find traditional print sizes tend to crop off too much of the scene, but printing them proportionally with no cropping makes them difficult and more expensive to frame. I think some of my best shots are on 6x9 though.
I like the 1.5:1 aspect too. I saw this saunders easel post recently:
(there was a url link here which no longer exists)
and if you look at the box in the photo, one of the "checkboxes" is "8x10 35mm full frame". I'll bet I'd like to have one of those. I wonder how hard it would be to find one. And yes standard frame sizes don't work all that well.. I'm thinking of buying a custom "sides and tops" in bulk. I also really like the old 122 format which is closer to 1.7:1. Custom framing needed for that aspect ratio too.