I bought my first digital SLR many years ago after waiting for the quality to improve and the price to drop. It was right on the cusp of it, because prior to the Canon 10D reports suggested DSLRs were inferior to film and they were too expensive. The reason why the first sensors were cropped in size is because they were so expensive to manufacture.
It was the same with full frame sensors concerning cost. Way too expensive. Then along came the Canon 5D and they became affordable. For a few years Canon pretty much dominated the market if image quality was your primary concern. Nikon would bring out a new model to equal Canon, then a month later another Canon model would set the benchmark again. Nikon eventually caught up and in some respects finally beat Canon. I don’t follow this stuff geekily but the D800 and D800E leapt ahead in resolution power and Canon stayed behind. The trouble is, you start working with excessive megapixels. Few people need that kind of resolution and if you don’t, you’re wasting storage space and the price of a computer which can handle those files. A photographer told me a few years ago clients were complaining his files were too big. If all you do is magazine editorial, even more so all you do is post pictures on the internet or make relatively small prints, a modest camera is fine.
Then came the Sony NEX and the Fuji X10, manufacturers finally providing good quality compacts after neglecting this part of the market. I tried them in a shop and the NEX felt good to use but not the Fuji. However the NEX has an APS sensor and struggles with wide angle lenses.
This for me is camera evolution. Your idea may differ because your values are different. We now see the Sony A7/R as the culmination of the above: it’s small, light, and very high quality.
I’m waiting for more reports. I have concerns about lenses and adaptors and using a Canon 17-40 or possibly a good Zeiss equivalent will be available. I need the wide angle. I shoot maybe 80% of my work at between 17 and 30 mm. I’ve seen reports suggesting the A7R which is the higher resolution version has video moire and aliasing. If true, it means it’s not in the same class as the Canon 5D3 which is disappointing. It is however a matter of degree. I don’t need super best quality in video and for other reasons – size, weight, quality – the new Sony models are going to be revolutionary.
I find it gratifying to see other cameras give Leica a good slap in the face. They are great cameras, we all know that, but they charge far too much for them. So take that! – because sales will now divert away from the M9 towards the A7/R. Not as solidly engineered but in several other respects better cameras and which will, if you’re lucky enough to have them, accept Leica lenses.