I use spot once and awhile, when it counts. Otherwise it is all incident at ISO 80, it seems to work well for me.
But then again, what the heck do I know? Some lo-fi windbags seem to not care for what I do on Kodachrome and have voiced it accordingly.
And I'll be honest, that has what has kept me and will continue to keep me from ever posting on here again, all technical, no talent, no photos and just talk from certain people ( Not you PE ).
But back on topic, incident works best for me as professional Kodachrome shooter.
Bye for good folks, 444 posts is a great number to part on!