For 30p project, shoot 30p or 60p? And why?

[MikeOfBonsall]

Seems to me, and this is what I am doing now, that even if your final project will be 30p, then shooting at 60p and rendering to 30p may have some advantages (like shooting at 1/125 instead of 1/60). Is this so or not a good idea?

[cws]

You're effectively halving your exposure, and reducing motion blur...  so it depends on whether that's a good thing for your subject/project or not, and whether you see any benefit in it.
By rendering to 30p... are you looking at throwing away half of what you've recorded, or frame-interpolating 2 exposures to get a single frame?

Need to be very sure of what you are trying to achieve... if its not a 2x slowdown.   Test.