hi bernard
i have been using the canon tsl 17mm and the sony a7r II for the last week, i'm not a critical user in a scientific sense but have pixel peeked for flaws as i'm going to use it for a work during the next 12 months. it is better than the d800e with the 24pce in terms of sharpness, contrast and CA and the camera is better than any digital 35mm i've used. i was so impressed with it's cousin the a7 II that i let all my nikon stuff go, happly, and that was before the a7r II. mind you i don't hammer nails all day long with my cameras.
sorry i can't post images at the moment as i'm out of town, i've found it works best, corner to corner, at f11. you have to be really careful with flare, the moment you let your guard down it'll turn up! the colour is not as nice out of the camera as the sony (zeiss) native 55, but that lens is amazing. i would certainly urge you to give this combo a try... be interesting reading all the upcoming reviews!