70mm: this setting and lower left corner seems to be a weakness of my IS. Edges are constantly blurry and L wipes a floor with it :)
100mm: IS is not so bad as @ 70mm anymore, but L is still sharper.
135mm: 135mm looks like a breakpoint in lower right corner. IS is very sharp at any apertures, while L simply can't reach sharpness of IS.
200mm: Pretty much the same situation as @ 135mm. IS clearly wins here, there's no doubt about it. L is blurry, no matter of aperture.