I've been playing with an A7R these last few days and in the end have decided it's not for me. However, in doing so it's made me appreciate better just how good m43 is. - The u43 system is very mature with a great range of lenses and bodies. You have cheap primes, expensive primes; cheap zooms, expensive zooms; coverage from fisheye to 800mm effective fl; bodies ranging from compact GM1s through to chunky high-feature bodies like a gripped E-M1. Aside from tilt/shift lenses there are no serious holes in the system. - The lens quality is mostly first rate (for a given price). Most of them are smaller and lighter than comparable optics from other systems. - The bodies offer first class usability and features including IBIS good to 4 stops, focus-stacking, 4k video, live composite, uber fast AF that works in very low light, hi-res stacking etc. - Despite the growth in size of the higher end bodies and the release of bigger and faster "pro" lenses, compactness is still excellent. I can pack my E-M1 in a small Bellingham bag with the Panasonic 7-14, 12-35, 35-100, Olympus 17/1.8, Samyang fisheye, small flash, filters and batteries. That's a serious bit of kit that will cover most things I need it for when travelling. - m43 is pretty affordable. Since I've been dabbling with the A7 I've been looking at prices in that system and there is a significant difference. - IQ is pretty darn good. I've been doing some serious pixel peeking against the A7R and of course the A7R is better. Noise handling is the big difference and there's slightly better tonal response - but you know, having printed A3 prints from both cameras I can promise you that the difference is very, very small. I doubt the A7 would make an image worth keeping that the E-M1 would miss. - I can be sure however that the A7R would miss shots that the E-M1 would get. Why? - because the Oly is faster, easier to use, quicker and more reliable to focus, allows sharp shots at much lower shutter speeds thanks to IBIS, and lasts longer between battery changes. I find nearly 100% of my shots with the Oly will be technically right. - The only area where m43 leaves me wanting is better noise handling. Having seen what the NX1, RX100 and A7Rii can do with their BSI sensors I'm feeling very disappointed with the new 20Mp u43 sensors which seem to offer little notable improvement. So, my plea for Olympus and Panasonic in 2016 is this: m43 is a great system, probably the best for many serious amateurs, but to stay there you need to make a step up in sensor technology. I know there is potential for organic sensors, stacked sensors, global shutters etc, but these seem some time away from commercial exploitation. In the meantime, can we just get some of the current latest technology?