I agree with Gordon here. I am not sure how visible the conversion will be, but certainly the rendering time will be slightly increased if you change the frame-rate from your time-line to the end product.
I would probably go with the 30fps version myself, as I will happily take every increase in the recording frame-rate I can get!
In my GoPro cameras, I have the option to switch between 25 and 30 fps (or 50/60 in one of the modes) and I never choose the lower one, unless playing back directly from the camera to a TV that will only take native UK refresh rate.
all the best,