So after a lot of thought and reading and encouragement here and other places I made the plunge all in with Olympus. My first digital camera was an Oly C4040 2 mp point and shoot around the year 2000. Then the E1 and a few more. Then the original OM1 which I passed on to my son in 2014 I think. I have the E-M1X now with a few lenses. Light and easy to carry and I am pleased. I have been testing out the 300 f/4 and I am slowly starting to get the hang of it. No crops and just a few adjustments in Lightroom. I am working on a birding area in my back yard with perches and have identified over 60 birds. Next will be to work on capturing them all through the seasons. I like to print and I am looking forward to it. The 300 is amazing. These are just snaps so I could test the camera and lens and work on settings. More to come as I get used to this.
Cardinal ISO 800, f/4, 1/200 sec, -0.7 EV
Black-crested Titmouse ISO 200, f/4, 1/640 sec, -0.7 EV
Try getting a little closer than that to really test BIF. For subjects that small in the frame you don't need any AI to keep things in focus. For example, out of an ~8 frame series this was the only shot with critical focus (EM1x pre bird AI). It is when the subject begins to fill the frame where things get more difficult and AFC is tested.