[Leica] Leica Lens Quality

[salex@idt.net (sam alexander)]

I was wondering if other Leica users had experience with variations in the
quality of a Leica lens. For example, back in the early 60's, I purchased a
new 35mm M-Summicron At Willoughby's (then a great camera store) in NYC.
After my third lens (!), I was satisfied that I had a Leica "Quality" lens.
. . the other two were definitely inferior! Subsequently, a 90 tele-Elmarit
purchased around
the same time was extremely sharp and contrasty! Another example purchased
shortly thereafter (first one was stolen) was not even close.
My question is, has anyone tested, purchased, or used different examples of
a given lens and found significant differences in terms of optical quality.
Ralph Feurbringer, a veritable encyclopedia of professional photography and
cameras/lenses in NYC buys a quantity of view camera lenses (he makes 6X12
shift panorama cameras based on the Brookes Veriwide body) and finds
significant differences between each lens he field tests. (Mostly
Rodenstock APO Grandagons). In other words, when a particular lens is
deemed extraordinary, are all examples equally so, or will some be
significantly less?
Just curious.