I love my M2. I think it is a much better camera than the M6.
I agree, much prefer the m2/3/4 VFs over the later brothers. Any VF irritation is to be avoided if it can be as far as I am concerned; this includes having no blinking, distracting/red-haze-causing lights in my M's VF for me! In my experience, the m6 flare was situational -- but when it occurred, it ruined the shot. If you shoot in situations where it occurs, it could be a hassle for you, too. That situational possibility noted, the M6 to MP VF upgrade is still a great deal less than buying a MP; you end up with a camera that is functionally the same as a M6 with one exception: the MP light meter is one stop more sensitive than the standard M6's. Yet using either a M6 or a MP meter in low light is a no-go for me -- it blinks and produces a red haze -- which has caused me to lose shots. Much prefer how the all-mechanical M's VFs just let me think, compose and shoot
"A great civilization is not conquered from without until it has destroyed itself from within." W. Durant