Ahh, Kodachrome. My first true love. And like so many, we have to leave that first true love behind and move ahead. But the memory never fades.
Such it is! My Kodachrome slides are as brilliant as the day I opened the box. But they were always a pain. First, a note on the process:
Kodachrome applied the 3 color dyes in the developing process, unlike Ektachrome and Fujichrome, which are chromogenic - meaning that the processing reveals the chemically-linked colors. That also means the dyes are built up on the surface of the film, which is another problem for scanning, as it's not a smooth surface.
Kodachrome had issues with color inconsistency, depending on the aging of the film. It would shift from green to magenta bias over time. Pros would test a batch and shove it in the fridge when it hit the right color balance.
I've been through the K14 processing line, and it's totally unlike other systems. It is a continuous high-speed line with film running through a zillion different processing baths. It's prone to scratching, too.
Scanning has always been tough, even for the high-end prepress scanners. I've used every method, and sometimes it's glorious, sometimes it's exasperating, even for similar images - like, why is there zero content in the red layer in this slide?
I've found that Silverfast tends to produce better results than Vuescan, most of the time. But not always!
Nowadays, I use a Nikon 5000 and, though Nikon abandoned their software, it's still the best dedicated film scanner, if you care about quality.
For speed, a transparency flatbed scanner can produce surprisingly decent results for multiple images of similar exposure.
Oh, and I have a nice Nikon Super Coolscan ED 4000 if anyone wants...