I often hear about how this lens is the sharpest in the Canon arsenal and how it is sharper than the 24 f/1.4 MkII. Now, I haven't actually used it, so can't make a comparison, however, I was looking at the reviews for both lenses on Photozone the other night. Photozone also states that this lens is the sharpest of the two, but the data they present tells a different story. Granted, it is undoubtedly a meaningless difference in the real world, but at every common aperture, the MTF figures for the f/1.4 are slightly higher then the TS/E. Photozone seem to be marking the f/1.4 down because it falls apart at the corners wider than f/2, especially at f/1.4. However, I'm not aware of any other 24mm lens that can even shoot at f/1.4, so the marking down is actually pretty meaningless. I'm wondering if people are actually taking more notice of such a fact and also that generally, you are shooting wider on a TS/E lens (and therefore more in the sweetspot), when they say that the TS/E is sharper. I'd be interested in hearing from anyone who is used to using both and has made a direct real world comparison for similar scenes. That said, the results are probably just as meaningless, as I needed a wide aperture for shooting the northern lights, which is the reason I went for the f/1.4 over the TS/E and Zeiss 21mm, otherwise it would have been a hard choice to choose between the three.