I like my 35L but it wasn't as mind blowing as I'd expected it to be. I've taken some very nice photos with it, but it doesn't have that effortless feel to it when taking photos, like the Sigma 50mm 1.4 does. Oddly I find the slow as a slow thing 85L to be amazing. So much so that the finished photo outweighs the slow focus.
I'm still wondering if Canon are releasing another 35L as rumour sites were saying there's a mkII on the horizon, but now this F2 is being bandied about I think that might be the new release.