I had a 27mm lens, because it was so small (with the X-E2), like an X100.
It is sharp... small... and thats all.
I liked it, but it is only a little bit smaller than the 35mm without the lenshood, wich is faster, focus is faster at low light, and has a very nice characteristic.
So XF27 is good, but a little bit boring.
Smiling eyes - Flickr