After owning an E-M5 for a few days, I can tell you that you need to spend some time to set up the camera the way you like (think). One thing with Olympus, is that most of their cameras offer a good amount of customizing. So think about what you want the customizable buttons to do.
Another thing you want to do, is “play” with the menu system, explore it, try to remember certain sub-menus that you use often. Spend some time with one “custom menu” option until you get it down.
If you do this, in no time, you will be mentally prepared to quickly adjust your camera and not miss your photograph.
I know how exited I got when I got mine, and how I wanted to got out and take a bunch of photos right away. But, take a few moments to at least see what things do by default is time well spent.
It really is a fantastic camera with a host of options.