Originally posted by Unsinkable II By IQ, I mean image quality in every sense. Wider dynamic range, less noise at any given ISO, more flexibility with DOF control. The lot. I'm sure the Oly will have very good IQ, but by virtue of its sensor size (to say nothing of the advanced Sony sensor design that Pentax seem to tweak extra magic from), it is destined to have poorer IQ than the X-01. I agree with your point though, for many people "very good" IQ is perfectly acceptable.
As regards M4/3 in general... well, technology marches on. 480P plasma TVs were the bomb when they first came out. Then 720P was seen as the entry level to HD TVs. Now it's 1080P. It will not be very long at all until we start getting cameras that record in 4K and TVs that will display 4K natively. YouTube already accepts 4K uploads:
4K resolution - Wikipedia, the free encyclopedia
Then there'll be 8K:
Ultra High Definition Television - Wikipedia, the free encyclopedia
So, as people's prime viewing medium improves, so will everything else. Including their prime capturing equipment. A few years down the road when you're reading reviews on M4/3 vs a mirrorless FF, the poor little sensor won't stand a chance.
Wait, so viewing mediums will improve from HD to 4k to 8k, and FF and APS-C will continue to improve to match these new viewing mediums, but 4/3 sensors are going to somehow stand still?
The size difference between APS-C and 4/3 (40% by area, a comparison biased by aspect ratio in favor of APS-C) has been exaggerated and harped on from day one, but the real reason for the difference in IQ between 4/3 and APS-C we're seeing is a result of Panasonic's mediocre chip design. If you cut one of sony's recent sensors down to 4/3 size, in equal-output-size comparisons (the only kind that really mean anything) there would be less than 1/2 stop of difference in DR and high ISO performance between the 4/3 sensor and the original. Probably less than 1/3.
Will APS-C always have a slight IQ advantage? Yes. But 4/3 not standing a chance? Come on, now. Oly is no longer tied to Panasonic for sensors (contract ended 2012) and Sony and Fuji have both immediately shown interest in collaboration with Olympus. Crop-sensor cameras are not going to lose their position as the bulk of the advanced camera market anytime soon, and if Olympus finally gets some competent sensor tech in their cameras there will be little sense in choosing APS-C over m4/3 from an IQ standpoint, unless that 1/3 stop of DR is a REALLY big deal to you. What will matter is ergonomics, optics, and the strength of the system, some areas in which Olympus is continually checking the boxes. On those criteria, honestly, I'd put it at the top of the mirrorless market. The current sensor tech (not size) is where it falls behind.
Personally I've come to love the low-ISO DR afforded by the sony sensor in my K-x, but considering the E-M5's 9fps and best IS on the market, I'd be happy to rely on bracketed bursts and a little extra PP for high-DR scenes. The other pluses of the camera (and system it's part of) more than make up for it, to me.