Like many I toyed with the idea of the A77 for some time, having briefly used one a few years back it was nice, but the price was fairly heavy at the time.
Fast forward to 2014 and a newer model A77 MkII and we get some very good deals on this camera right now.
Having used the camera for a week or so I'll give you my honest impressions of it so far, and will update the review as required over time.
Quick fire good/bad points
+ Very good build, mag alloy front and back panels, weather sealing (dust moisture)
+ Excellent 19 point (11 cross type AF points) autofocus, it's very fast with good accuracy
+ Ability to AF "fine tune" lenses (so far I have not needed to)
+ Built in red LED beam "AF assist" very handy for low light, it puts a pattern out and you can focus even in complete darkness or on subjects with no contrast
+ Excellent details and tonality with very good dynamic range, 24mp is overkill for most, but the firepower is there if you need it
+ Extensive on body controls with direct buttons for WB, ISO, joystick control, front/rear dials, AF mode knob
+ Top LCD can be useful (it's backlit) for tripod shooting
+ Multi swivel LCD can be fully articulated, sharp high res 3" display
+ Very fast frames per second shooting rate up to 12fps (fixed aperture though) also has 8fps and 3fps cont shooting modes
+ Full metal mount (lower priced alpha bodies don't have this, just worth a mention)
+ Focus "peaking" can be use and a magnify focus check, this makes manual focus very easy
+ Ability to "save" 3 banks of settings on the dial (MR position)
+ Has a DOF preview, DMF (direct manual focus) option for AF
+ PC sync port, remote port, GPS built in, 3.5mm microphone
+ Quiet shutter sound (electronic first curtain) Shutter rated to 150k actuations
+ 1/8000 sec top shutter speed
+ Steady shot adds in body stabilisations to all lenses (even older Minolta and third party A mount lenses) for free
- Battery life is around 500 shots below comparable DSLR's
- Some limitations to movie mode, Auto ISO is limited to ISO 1600 max, the video also crops in more, AF is restricted to f3.5 even if you have faster lenses, cannot adjust audio levels (though sound quality is good - stereo with wind cut function) You do have manual controls though (just not AF)
- Jpeg noise reduction is too strong for my own tastes, ok at low ISO but higher ISO levels you are better off shooting raw (and you are best shooting raw at low ISO for max details)
- High ISO/Low light shooting requires more care with exposure (metering can underexpose) ISO 3200 is usable with decent exposures, 6400 is pushing things a little.
- LCD can't be seen properly if turned around facing you if there is a flash in the hot shoe
- ? Button is only useful for image deleting (you can bring up a guide mode with it - option in the menu)
Other notes: (I will update this as required)
OLED EVF is good resolution wise and has some benefits (focus peaking and exposure simulation, big view) it does struggle with dynamic range in harsh lighting though, and there is some noise in low light in the viewfinder (not listed this as a pro or con like an optical finder it has advantages and disadvantages) The live view advantage due to the fixed mirror is that you get phase detect AF in live view full time (though the 70d has this off the sensor too), the mirror does take a bit of light though for the AF system (I estimate about half a stop)
Buffer depth is around 15/16 frames raw (shooting at 8fps) that's ok though the newer A77 II has a significantly bigger buffer, it's probably enough for most (quite a lot larger than the D7100 buffer, similar to the 70d's buffer), the A57 I have shoots around 23 frames at 8fps (buffer the same smaller raw files mean more shots)
Do get yourself a faster card if you shoot action, I tested the 80MB/s Sandisk in camera and it's clearing times are quick, likewise the Extreme pro is a touch faster, the 45MB/s Extreme is acceptable clearing times wise (longer than both but not bad) The A77 is UHS-I compatible so look out for cards that are compatible with that from various makers. A normal class 10 SD card is fairly slow to clear a big burst, one to watch for if you shoot higher frames per second. If you're a landscape shooter it's not really an issue.
Firmware it's running 1.07 out of the box (this is the latest update) this cured some lag issues and flash exposure problems (no issues here to report with flash so far) Menus are quite easy to use with good customisation, though not quite as comprehensive as similar Canon/Nikon bodies.
You can set various buttons to different functions such as the AEL button, the ISO button, AF/MF button on the back, some of those might be handy for other functions, it's a shame you can't customise the ? button though. Like the 7 series cameras from the past era (Minolta and Sony) you can set the rear dial to exposure compensation.
Operation and performance are snappy with fast autofocus, it does take a while to get used to the controls the rear joystick is handy for directly setting the AF points. You have wireless flash control via the built in flash (as you do on all Sony bodies), you can additionally set the A77's built in flash to manual output (1/16 min output) this can be useful for triggering optical flashes without the main flash influencing the exposure.
Exposure is good in most situations, even in harsh light it balances exposure well, but in lower light levels it can be a bit under, this won't do you any favours with high ISO shooting, so adjust the exposure if required underexposing at high ISO will increase noise. The A77 isn't as bad as some make out in this area (1600 is good, 3200 if done with care can yield good print sizes..above that all APS-C models tend to struggle at ISO 6400), but it's not quite up there with the Canikon's on this. Still you do have stabilisation built in, you might be able to compensate with that.
In terms of overall spec it's comparable to the D7100, and 70d in many ways. These bodies all have good and bad points, and are considered to be "semi pro" level ie they have enhanced build over lower priced bodies, faster max shutter speeds, more functions and customisation of controls (and many more direct controls)
The EVF is something you'll have to decide on yourself I have got used to it (to a point) it does have some advantages, and some downsides. Manual focus is very easy now, you get a real time exposure preview, it can gain up in very low light, and can have lots of information on the display. Downsides are clarity isn't as good as a good pentaprism optical finder (details) and it can struggle a bit in very contrasty light (shadows can be crushed a bit), following action is harder too (last image displayed rather than current one) and battery life takes a hit. A personal choice here worth trying one if you can in person.
On balance though, at this price a bit of a sleeper bargain if you are invested in A mount and were holding off on the A77 due to cost, well now it's a lot more affordable and wallet friendly. Will update the review with additional thoughts over time (with more extended field use)
The supplied 16-50mm f2.8 I have only briefly used, it's a constant f2.8 aperture and is weather sealed with SSM (super sonic motor) which is fast and very quiet. It's a decent lens similar in optics to the Tamron 17-50mm f2.8, though the Tamron has the edge in sharpness at the 50mm end, and a little better in the corners.
Still a good bundle deal for a weather sealed kit