70mm: L is a clear winner wide open in the center at 70mm. At f5.6 and f8 the results are pretty much the same and I doubt you can see any difference between L and IS on prints.
100mm: L is still sharper here, although the difference is very very small, probably invisible in real life.
200mm: the same situation - L is sharper in the middle of image, especially at bigger apertures. At f8 sharpness is getting almost the same.