I've seen it written several times that lenses now work as they were intended to on the M9.
I've been thinking about this some and trying to get my head around it.
The obvious answer is that a 35mm lens now has an uncropped 35mm angle of view. So, for those of use who grew up with 35mm film (I did), we have true match between focal length and what we're used to. But, I think you can get used to this initial "cognitive dissonance" or, if you've grown up only with digital cropped sensors, it doesn't mean anything to you.
So, is there more?
One thing I noticed when shooting with a 35mm on a cropped camera (I mostly noticed this in my prior Canon days, but should still apply) is that I felt that I got some distortion from the 35mm that I didn't get from a 50mm all else being equal (i.e., filling the frame with subject, etc). That is, I felt that I got better results with full frame portraits shooting full frame using a 50mm lens than shooting cropped frame using a 35mm lens purely on the basis of distortion.
Then there is depth of field at a given subject to camera distance (e.g., to get a 35mm "full frame view" with a 35mm lens on an M8 would require me to stand back farther than I would if used on full frame, thus altering DOF).
Then, maybe there's something else. Something more technical vis a vis lens design and how it matches with full frame. Or something else more cosmic . Or, maybe there is nothing else and the whole issue about full frame is simply related to crop factor and the availability of lenses to get a certain angle of view with a certain aperture.
So, what are people's thoughts about the potential differences between the full frame vs. cropped sensor vis a vis how the lenses used for them might render differently.
(NB: I am not asking about specific lens availability for different crop factors. I also am *not* trying to argue for or against full frame, nor am I trying to defend or attack what I've read on this topic. Just looking for an open discussion on the topic)