Yes it misses focus sometimes, but I don't think its because its "slow" and the bokeh is not pretty if you have a lot of contrast, but srsly for the price its a gem of a little lens. Sharp sharp sharp. Really fun for family candids and less "important" stuff, and more importantly so I enjoy shooting when I want too.
Sharp and quick here!
Perfect for walking around NYC with kids, and wanting something better then my iphone pics and the only other camera's I have are FF