I wrote earlier that I did not see much new for me in PL4 and one of the responses mentioned the new DeepPrime NR processing. While I almost never use flash when taking photos I have mostly been shooting with large aperture lenses lenses outdoors during the day so the highest ISO I have used has probably been 1000, not enough for much noise.
But based on the post I decided to take some photos at ISO 6400 with my Olympus E-M5.3 and see how good the NR functionality is, and those photos convinced me.
Here are some crops:
That is pretty impressive.