This lens, along with the 35mm f1.4L, are two of Canon's best known wide angle primes. After owning the Canon EF 24-105mm f4L for a couple of months, I can't say I like that lens very much, not because it's optically bad, but because it's a zoom, and a slow one at that (f4). Sure it has Image Stabilization, but I love primes, especially fast primes. So, basically I swap the 24-105mm f4L for this one.

Haven't shot many frames yet, but for the small number that I did, it's encouraging. Will update as I use this lens more.