The more I shoot with OMD EM-1, the more I'm impressed with it. I don't think it's fair to compare EM-1 with full-frame pro-grade DSLR cameras, but considering other factors such as size, weight, price and image quality, EM-1 is one hard camera to beat. I will choose this over any other APS-C cameras any day.
Portability is the name of the game. There are other options in pro-grade compact camera segment such as Sony a7/a7r and Nikon df. Nikon says it is the lightest and the smallest DSLR of Nikon line up, but honestly I think it's too bulky to be considered as compact. Sony on the other hand, is super compact and light! Kudos to Sony. They're the first to pack a full-frame sensor in a compact body with auto focus. But what is up with their lens line up? I personally wouldn't consider a new camera unless fast 24, 35, 50 and 85 are available. Sony's new full-frame compact body camera a7/a7r is probably the best compact body money can buy on the market right now, but it can only do so much without a proper lens set up. And Sony really needs to learn how to make the lens smaller to match the camera. What is the point of getting a compact camera if it ain't portable with the lens attached?
I initially purchased EM-1 for my daily use, but I'm at the point that I am considering to get more lenses and perhaps one more body. Okay, maybe I will wait for OMD EM-1 mark ii or something, but definitely interested in other lenses such as M.Zuiko 60mm 2.8 macro and 75mm 1.8. Olympus started to make M.Zuiko PRO lens line up with 12-40mm 2.8 and the development of 40-150mm 2.8 has been announced. The rumor says there are two more pro lenses coming in 2014, super-telephoto & ultra wide-angle. I can already see my wallet getting thinner and thinner.