I'm just so torned, it seems like all 20-35mm fast primes are compromises. The 24 1.4 has a reputation for softish corners, the 20 1.8 (sigma) is soft at 1.8 (dreamy, gauzy). The 35 1.4 isn't really wide enough... Life is hard!
I love my 24mm 1.4L glass for landscape work. The bokeh is very nice, and the contrast is really excellent. Even the corners are fairly sharp. I just wish Canon would update the 24 TS-E lens so I could buy it for landscape work :)