Hi,
I use both canons: 17 mm and 24 mm II on sony a7r with Metabones 3 adapter and it works very well.
I modifyied the adapter as was described in the forum to eliminate inner reflexions.
The 17 mm can be used with full movements, when you shift to the maximum you need to use App. 11,5 or 16 to get sharp borders. Also exact use of live view in necessary. I find this combination the most compact, fast and very exsiting for architecture needs.
I added 35 mm Zeiss distagon PC and Mamiya 50 mm shift to this combination. Hartblei-Zeiss 40 mm would be a next step but nor really cheap.
all best
roman