I have both the E-M1 (and had an E-M5 before it was stolen) and the A7r, and feel they complement each other really well. I won't say Olympus is 'intuitive' - it's highly customizable, and once you figure out the best setup for various custom functions that works for you (bit of a challenge, with the various custom button options, now two extra on the front as well!) you get a camera that's finely tuned to how you want to shoot. The A7r is easy to use out of the box, and has a decent level of customization, but isn't quite as slick/complete as the E-M1.
how are you guys finding the low light high iso ability of the A7, like 3200+?