Hi there, a response to the difference between the 40 and 50; Alan had made a comment about a year ago on that, and he stated that "The M50ti has quite a bit more clarity and detail than the M40, but not quite as much as the M60ti." At some point after that the advertising comments that I believe you are refering to, had been changed to reflect a differing company philosophy.

Just an observation. May be flawed. Maybe not.
Rich.