50mm preasph lux? which one is I and II ?

[JNewell]

I would also bet money that the newer version (with the collapsible hood) is built to higher tolerances

You are probably right, but the other side of that coin is that several newer designs have proven to be designed in ways that rely on methods that are less durable mechanically than earlier designs. I am thinking, for example, of the reports of the v4 35mm (pre-ASPH) Summicron lenses coming unglued. Trade-offs, compromises...no magic bullets (or perfect lenses)...