Small and very light weighing in at a mere 55g it packs a bigger punch than it's reputation. Just my opinion of course. It's actually so small it looks out of place on the bigger MFT bodies. It's a 28mm equivalent on FF so it might not suit everybody.
However, mount it on one of the smaller bodies like a GM1 or GM5 and you have a perfect carry everywhere camera system.
Price point today for version II of this lens is €199. My copy is the older version I but it still produces some sharp images.
Optimal aperture is around f4 - 5.6 and I would not go past f5.6 as diffraction starts to show it's ugly head. Photographers tend to find image quality ok with their present lenses, until you try something new. I did that mistake in this case and got the Panasonic 15 f1.7. CA and flare are better controlled and it is a sharper lens.
If you are thinking about a lens in this focal range, just do yourself a favour and get the Panasonic 15 f1.7, however I can't speak for the secnd version of this lens as I haven't tried it.