Dave, here is a breakdown of the versions of the 35mm Summilux in order of their release.
ASPH means aspherical lens elements, and FLE means floating lens elements.
I'm sure I forgot a version of the lens somewhere.
I've owned or used every 35mm Summilux, except the "AA" and I like the pre ASPH versions best for their characteristics.
35mm f1.4 Summilux Steel Rim, first version lens, non ASPH lens.
35mm f1.4 Summilux version II, a non ASPH lens.
35mm f1.4 ASPHERICAL "AA" Summilux, rare lens first ASPH version 2000 made.
35mm f1.4 ASPH Summilux, ASPH lens.
35mm f1.4 ASPH FLE Summilux, an ASPH lens with corrected floating lens elements.