I stopped using Kodachrome in the early 80s when the new generation of Fujichrome hit the market. Fujichrome 50 had the same grain and sharpness as Kodachrome 25, much better colour rendition (especially fleshtones), cost less and could be processed anywhere.
Turncoat! Quisling!
I Think what I will miss most is some of the great Black and White films which digital doesn't seem to be able to come close to. PanX developed using direct positive to produce Black and White transparencies is absolutely beautiful. If you have never tried it, you should before it's gone. Also, I forget the film name right now, but there is a scientific B/W film that you can use a special low contrast developer for that produces sharp 4’x6’ B/W prints with almost no grain at 12 ASA.
I will miss film so much. Kodachrome, Fujichome, PanX, CibaChrome, Tri-X, VPS, etc...