I am going to check this lens out tomorrow. The thing I like about this lens from specs is that it is lighter and smaller as the Sigma 35 f/1.4, it has IS and f/2 (compared to the pancake 40mm)
It may be a better indoor/streetphotography lens on my 6D as the Sigma 35mm - which is bigger and heavier.
But I am still in doubt...
Why is how heavy this lens is even that important? It's true that technically the Sigma is heavier. But you're talking about an item that weighs less than two pounds. That's a pretty pathetic complaint in my eyes. It weighs less than a bottle of soda or water. C'mon guys, if you spent the time you spend complaining and talking about lens weights in strength training, you wouldn't have anything to complain about. Pick up a weight or two once in a while. Lenses aren't heavy.
Random Orbits and zlatko make the valid points here.
As you can see from my signature I own some heavier lenses than the sigma or canon 35mm. My 5D MKIII als comes with a grip and usually with the GP-E2. So, I am used to carry some weight and it is not an issue for a 6"2 person unless carrying it all day. BUT....I bought the 6D (using it without grip) also to be able to go somewhere light - indoors or street - with an aperture sensitive lens (more than 2.8 in focal length of 35mm (otherwise I could take my 16-35mm or 24-70) And, I do not want to use a large camera with a large lens to bump into peoples faces or scare them off. Point and shoot camera is not my choice.
But everyone has its own criteria