I have not had auto-focus issues on my old E-M1, current E-M1 Mk II or GX850, other than DoF being so thin at f/1.4 that if the focus point is on the wrong place it is very unforgiving, hence I only use the small focus point. It focuses slower than the 12-40mm f/2.8, but then so did the PL25 that I used to own, and apparently the 75mm f/1.8 as well I hear. It's certainly fast and accurate enough for me to get action shots of my three year old with C-AF stopped down to f/2.8, or more static portraits in S-AF at f/1.4.