I've only had it for a couple days so I can only give you my first hands-on impressions, but here's how I would (re-)order the pros and cons (for brevity, I won't relist any point that I agree with):
Pros
- Small, innovative design : but comfort may vary; With the screen tilted up (shooting from the waist), it's surprisingly comfortable to use an overhand grip with the thumb on the shutter release. In a standard grip with the first finger on the shutter release, some people may find the lower right of the camera body digs into the palm.
- Metal barrelled lenses feel impressive compared to peers : But only the outer casing on the 18-55mm; at the tele-end, the barrel extends, revealing a plastic section which has a little play. Not terrible, but something to keep in mind. Fortunately there's no zoom creep at the wide.
Toss-up
- Built-in user guide (Shooting Tips) : I'd like an option to turn it off and reassign the unused button to something more useful. But if you're just starting out and need to refer to it constantly, it's a nice addition without having to dig through help menus or carry around a booklet.
- Consumes battery very quickly if you use the screen a lot between shots : so far in my experience, I find this to be true when compared to shooting with a DSLR (I have a 5DM2). But it's not so drastic, and I think if the target market is comprised mostly of P&S users who are content with taking snapshots throughout the day (rather than pros who can easily exceed 1000 shots in an assignment), the battery should suffice. YMMV.
- Screw-on flash awkward to attach : Yes, but if you shoot outdoors a lot and seldom need the flash, this might not be a big issue. We also have yet to see what other accessories Sony will make. If Sony releases an EVF, I will most likely keep that attached and just forget about the flash.
Cons
- Lack of function menu makes settings changes in PASM modes unnecessarily long-winded : This is certainly true, but I can't say yet if this is going to become a nuisance. On the other hand, for a new photographer, the menu (even if organized somewhat arbitrarily) looks simpler to use compared to a DSLR, so even though it's more difficult to change settings, it could be "psychologically" more user friendly. Toss-up.
- Slow startup and poor shot-to-shot times compared to a DSLR : Definitely not as snappy as a DSLR, but not infuriatingly slow. Interestingly enough, when using A-mount lenses with the LA-EA1 adapter, the startup time is much faster. Of course A-mount lenses are (currently) MF-only.
- Very limited video control (no aperture control or exposure lock) : Canon was able to fix this problem on the 5DM2 with a firmware update. I'd like Sony to do the same, but I won't get my hopes up.
- Live histogram unavailable when making exposure changes : Changing EV is easy to do, but without the histogram, you have to rely on the display for judging exposure (or else be patient and review your pictures). When outdoors with sunlight affecting the readability of the display, this will be problematic.
Other thoughts:
Regarding MF assist (live magnification): When using A-mount lenses with the LA-EA1 adapter, the
lower soft button changes to "MF assist", so in order to activate it, you need to stretch your thumb back to reach the button. Depending on your hands, this may cause your hand posture to change and may make focusing on a subject (temporarily) more difficult. With E-mount lenses, MF assist is automatically activated when turning the focus ring, but you will still need to reach back to the lower soft button to toggle between x7.0 and x14.0. Not the most annoying problem, but assigning MF assist to the
top soft button would make it a little easier to use.
I only have the 18-55mm kit, but the AF motor is
much quieter (almost dead-silent) than on my Pana 20/1.7. That might not be a good comparison though, so take it with a grain of salt.
I stopped by the camera shop and tried the SAL70300G and SAL2470Z. Size and weight are
not a good match.

However I think something like the SAL85F14Z would actually be a nice match. And even though the LA-EA1 adapter adds to the size, it actually gives your left hand more room to work, rather than keeping both hands cramped near the mount.
This is a very small detail, but vertical strap loops are
wonderful . They help keep the lens pointed straight down, rather than keep the body horizontal with the lens pulling it down at an angle. With a strap crossed over your shoulder, the camera feels like it hugs your chest.