How about the grain when you push Provia? Any noticeable change?
I'm wondering as well, is there any advantage to pushing 100F as opposed to just using Provia 400X?
I shoot slides for projection, and no, I honestly don't see a difference in grain when projecting at 2'x3'. I've not shot 400X yet. Usually when I think "I need 400 speed film" it's too close to the time I'll need it to order from B&H so I just push the 100F to 320. Shooting 400X at box speed would get me an extra 1/3 stop though, and probably less contrasty than pushing 100F 2 stops.
Shoot more film.
There are eight ways to put a slide into a projector tray. Seven of them are wrong.