The 18.5mm f/1.8 is a sharp lens, even wide open. And sharp lenses tend to produce relatively harsh (as in opposite of creamy/buttery/smooth) bokeh. That seems to be the case with the 18.5mm as well. More often than not, the bokeh is harsh, and it isn’t easy to achieve bokeh with the small 1″ sensor in the first place. You really have to stay away from foliage. However, pleasing bokeh isn’t downright impossible with the Nikkor. You just have to be careful and avoid “nervous” backgrounds.
I’m very pleased with the high ISO performance of the comparatively tiny 1″ sensor. IMO ISO1600 is perfectly usable. ISO3200 on the other hand is more situational. Sometimes it’s all good, other times it’s noisy as hell. I guess you have to be much more precise with exposure when using ISO3200. However, that is nothing new to me. High sensitivity film behaved the same way. The higher you go, less room for error you have.