[...] All three [original A7's] use Sony’s 11+7 bit lossy raw compression that can result in posterization at either end of the tonal range if any serious processing is required. Color accuracy also suffers a bit. I think there’s no clearer demonstration of this than the fact that the A7II’s raw files are always the same size; at higher ISOs, the OOC JPEGs are actually larger.
We still have a 24MP FF sensor that has PDAF photosites and EFC capability; it’s now suspended in a magnetic IBIS system that’s strikingly similar to that used by Olympus (and supposedly it uses both in-lens and in-body systems when a suitably equipped lens is mounted). I suppose it should be no surprise that Sony got some technology in return for the bailout funds they injected a couple of years ago. [...]
[...] In practice, [the stabilizer is] good for about 2-2.5 stops; not quite as effective as the Olympus system, but this is not surprising given how much more mass there is to move around. [...]
[...] Curiously though, I noticed that the stabilizer seems to be most effective when the camera is held horizontal or vertical; if at a significant tilt up or down, or rotation (or both) it seemed qualitatively less effective, by perhaps about a stop.
[...]
AF performance remains much like the A7: fast enough under most situations, but slowing noticeably when the light level drops, or with a slower lens. Accuracy is fine when there’s enough light, but again – when it gets darker, you’d better get a second shot for insurance. The camera has a tendency to pick a different distance every time you refocus, especially if the background and foreground distances aren’t that different. It has PDAF pixels on the sensor, but the reality is it still won’t track as well as a traditional DSLR. There are pre-focusing options as well as eye-sensor triggered AF start, but they don’t really speed things up that much and have quite a noticeable effect on battery life. Viewfinder and LCD refresh rates are both fast enough for most uses, but you might be aware of some lag if you’re shooting rapidly moving objects. On the subject of the EVF – both monitor and LCD use OLEDs; there’s nothing wrong with the panels themselves, but the optics used for the EVF could be better; a bit more magnification would help, and there’s too much distortion unless your eye is dead center. It’s not as bad as the GH3’s EVF, but nowhere near as good as the E-M1 or X-T1, either.