Otherwise, the lens is very pleasant; good to very good sharpness, low light sensitivity.
As alternatives to MFT there is still the Panasonic 7-14 and probably soon also an Olympus 7-14; both, however, significantly larger, more expensive and wg. aausgewölbter front lens is not screw-compatible.
The 9-18 is therefore the sum of the most practical features MFT UWW, but at the far end is not as spectacular as other lenses.
==== Addendum after several hundred shots =====
It remains at 4 stars: The picture quality is at a high level; the UWW perspective is OK and just on the border, so that images are not completely "crazy" look.
On "long" end of one is exactly in the "reportage focal length" of ~ 35mm KB; very convenient.
However, my e-M10 has occasional problems, sharply observed on AF - to that extent I find the only at the 9-18. My other Oly lenses do not exhibit the phenomenon.
All in all, the 09-18 currently because it combines for Olympus users there is no alternative, compactness with very good image quality with filter thread.
Should Olympus eventually release a filter-compatible 7-14, I'm going. :-)