Do you have to go into the menu to set wysiwyg?
Yes, it is not assignable to any button as I can see. My solution, not the best but sort of works: Two exactly the same Mysets good for 90% of the way I generally use the camera, except for the Wysiwyg change. Assigned one to IAuto and the other to Art on the mode dial. Problem, if I change anything like ISO, white balance, burst rate, etc I loose the changes on the Myset change and must reset them. This rarely happens in practice, except for ISO, so it does not bother me much. I can live with it. But would like to be able to assign it to a button.
Track focus. Will it track focus with mft lenses and keep in focus?
I have only tried tracking with the 4/3 50-200 lens. Since I have no experience with other than mft cameras in the digital realm, I can't really compare it to anything. But I did not like it. Shooting dirt track cars did not work well for me. In 4/3 phase mode, the area of active focus is somewhat limited to the central viewfinder area, so I kept loosing the cars focus. With mft lenses it might well be a different story as the focus area is almost the full viewfinder but I have not tried it.
After three weeks shooting the cars on Sundays, I found what works last Sunday. Very sharp results, in focus. Just use single AFP and aim it at the damn car if you can see it through the dust. It got focus fast enough in this case. Again, with 4/3 lens, phase focus. What did not work was my usual prefocus technique. I usually focus on a spot on the track where I know there will be action and hit it when the cars reach that point. The camera would not focus on the track as there was low contrast and no vertical lines. You need vertical lines for the phase focusing as the sensors are not cross type, only laid out on a horizonal line.
Right Angle Grip. Do you have it, and/or is it out and do you know when?
If you mean the battery grip, it is out and I have it. Nice. Very useful for the larger lenses like the 50-200, not required so much for average lenses. Of course it does double the battery life if that is what you need.
I also got the RRS L-bracket for use without the battery grip. Disappointed as you cannot easily use the remote camera release with it attached. Of course this is a tripod accessory and as such one wants to use the remote. The GH3 got this right as the remote socket is on the right and free and clear.
I don't do much high ISO so can't comment.
Generally, I like the camera but wish Oly would set up their focus system like the GH3. Got the Pana GX7 at the same time and really love that camera.