The C14 is f/11 whereas the C11 is f/10 so for extended objects he is sort of right but only for sensors with the same pixel size.
Even there, since the C14 image will be (more) oversampled, the images could be filtered to match the seeing (which limits the image resolution here) and then other than some extra camera read noise from the larger number of pixels covered, the two images would contain the same information but the C14 would need less exposure time. I could perhaps even argue that with CMOS sensors the increased oversampling with the C14 might give a greater potential for filtering the non stochastic telegraph noise.