The TS-E 17mm f/4L is reviewed in DAP.
I was favorably impressed with the TS-E 17/4L, though my particular sample had a problem, which I document in my review.
Architectural and landscape photographers in particular should be looking at this lens, but landscape shooters will find it a highly versatile optic.
The 17/4L would be the first Canon TS-E lens that I would buy, were I in a buying mood for such a lens; it’s excellent and absolutely unique. I’d love to own one, and only the price holds me back.