The 35mm IS a gem, as above.
In my opinion, on the X-Pro1 I would rate it as "adequate" totally usable. No problem.
On the X-T1 I would rate it as "fast enough".
You'll forgive the slight lag when you see the images you create. It has the magic. Take our word for it.
I just walked-up and fired the shutter at this yesterday.
Oak Flats by Josh, on Flickr