Summary: Great optics, very sharp. But autofocus it's slow and useless in continuous mode (with X-T1 at least), since it never locks and always keeps searching near the focus point, but without locking as it does on single focus, or as any lens do on continuous focus on any DSLR.
Excerpt: The Fujifilm XF 35mm F/1.4 lens produces high quality images with nicely saturated colors and decent contrast. Out of focus areas are smooth. The only negative is that it makes a lot of noise when focusing or even when switching from taking photos to viewing them.
Optically amazing, but it's loud and slow to focus with Fuji X-T1
17 June 2014
Summary: It's really hard to summarize this lens. Optically it's amazing. The bokeh is gorgeous and wide open you get a nice background separation. But on my Fuji X-T1 with the newest firmware (ver 3.1) it's considerably slower to focus than the 18-55 mm and it is really loud. When taking portraits of my friends they notice when the lens is focusing because of the sound it produces. In continuous focusing mode it's useless, it cannot lock to the subject at all.