I've recently upgraded from a 7D to a 6D and among other things, I'm liking that its smaller and lighter than my old body. I normally carry a film body around with me so I try to keep things light. My nifty fifty is seeing much more use because its more suited to FF than a crop body but I would like a wider prime.
I was looking at the Sigma 35mm Art but its quite a big and heavy lens for a prime. Its about the same size and weight as my 24-105L. The EF 40 STM is not quite as wide as I'd like but its size and weight certainly appeals. I've read some reviews but I'd like to hear the opinions of shooters who actually own it please 



