This is a very good lens and should be in any self respecting Fuji X-Pro1 or X-E1 owners bag. It feels solid and is very well screwed together.
I’ve had rubbish weather to test out this lens and I’m upset I cannot replicate the very bright conditions on Sunday when I first road tested the lens. Nonetheless the rubbish weather has enabled me to confirm the lens OIS works well…
Using it with the X-Pro1 OVF takes some getting used to in that the size of the frame is tiny at full zoom. That say, it is perfect for action shots as you can see what is happening around the frame. I didn’t mind using it with the OVF in that way but I preferred to use it with the EVF.
The lens has a fast and (scarily) quiet auto-focus mechanism and uses an internal focusing system, which means the front element and filter thread does not rotate on focus. Focus speed is very good, much better than any of the primes except the 18mm, and I suspect the original primes will be quietly upgraded to use the linear motors used in this lens over time. However, sometime the 18-55 feels more inaccurate at focusing than the primes. This seems to be some that was addressed in firmware for the primes so I wouldn’t be too worried about it right now.
The lens is very sharp and compares well with constant aperture zooms I have used. By way of comparison I think it compares favourably to the 12-35 for M43s in that it is almost as quick to focus, is ultra sharp (though the sensor helps here) and the OIS is very good. Also the 12-35 suffers badly from CA on Olympus bodies. The 18-55mm only really loses out because of its aperture – ultimately the 12-35mm is better in low light because of that.
Distortion isn’t too bad and is only really noticeable for me at 18mm (note, distortion is corrected in body). There is some barreling at 18mm, but no pincushion distortion I noticed at the 55mm setting. Bokeh is very good at 55mm but is a little busy at 18mm. Vignetting is not a problem.
Quibbles aside this is a very good lens and is a steal for the £529 I’ve seen it advertised for. Basically, get it as soon as you can. You won’t regret it!