Thanks Shaun, I thought that was the case regarding the S for selectable frame rates... We're in PAL land and not going to do a film out or anything like that so we'll be shooting at 25PsF and for high speed, we'll just ramp it up to S50P.
Mitch, thanks for your answers too (at least you've bench tested the camera!). It will be nice to use the optical ND's in 1 stop increments, so using the Electronic 5600K option sounds like a good idea.
I will keep in mind the notion of not mixing variable speed shots on the same tape, but we could get stuck if our stock runs low. A colleague of mine was recently at a Post house where they were having all sorts of trouble locking their deck up to variable speed stuff shot with the F23. They said the material was going from 59.94 to 60 and all over the place and they couldn't get it to digitise. Also they had problems grading the material that was captured with the S-log. Apparently they said that there wasn't enough chroma information in the image to bring it back to a natural look without introducing a lot of noise. Though they were trying to grade in Shake or After Effects, not a true grading suite. A guy from Sony came out and told them they should have shot 709 linear... don't know why, if they intended on grading it?
Thanks for the tip on the homemade shoulder pad too, I'll try and whip one up tonight.
Matt