Erik van Straten
Veteran
Steve may have different reasons, but for me limitations would be 1) Availability, they are no longer made and good clean examples are ever more difficult to find, 2) Price is very high compared to other newer offerings, 3) Very glowy when shot wide open against strong light.
That said, I shot with one for several years while working as a photojournalist and liked the lens very much, but the reasons above keep me from buying one.
But the pre-asph 35mm Summilux was made in many versions, also optically. The first Leitz Summilux 35mm lenses were made around 1960. There were many optical and mechanically differences between the lenses. I remember that the German made 35mm Summilux was much more expensive than the Canadian ones, with the exception of the steel rims. It is in al honesty impossible to generalize about all these versions.
Erik.