After 4 days of using the
old hardware with the new firmware, my intermediate findings are:
A lot of improvements, especially since I unboxed the camera 5 weeks ago (with firmware 1.0). Functionality in terms of AF became better, low light shots are no longer a huge problem. Which doesn't mean a 100% keeper rate. Camera and I not always agree on importance of objects to be in focus. So, a couple of shots I didn't make.
Others were at something like 6400 ISO, 1/20 and aperture between f/2 and f/1.2
The Auto-whitebalance does a nice job - the light was clearly worse than here to be seen.
And the 35/2 is although on the limit with 1/20" still useable in terms of AF
But still no tongue-detection

Maybe firmware 5.0 will have some new goodies.