this. The bit down the bottom about Monet is especially interesting, years before colour photography and computers.
But between negs and slides, no idea. I've just been scanning a very-expired Gold 400 shot on my 1/2-frame Agat 18k. Having no lightmeter, and very expired film, a lot of them were underexposed. Those had massive grain even viewing on-screen at 4x6 print-size. Others were perfectly exposed and the results looked good enough at about 8x10" print-size.
In lab conditions, with a certain MTF/% definition of 'sharp', maybe Velvia beats most negs. Maybe Ektar even beats Velvia. but go out in the real world and shoot something else, and the results might be different. (wow, i think I've heard exactly the same thing on gear-head forums about the D800e vs D800 vs 5D3 and Zeiss lenses vs Canon's L)