ActuallyYou're asking for input (opinion) so I'll jump in with a few thoughts.

I own the following Canon bodies: 10D (converted to infrared), 5D (backup camera), 7D and 5D MII. Contemplating selling the 5D and 5D MII and buying a 1Dx and 5D MIII. I own a lot of Canon glass and accessories to the extent I have 84 points in the Canon Professional Services Program. (Not braging but to let you know where I'm coming from)

I also own a couple of Nikon PS's, a Canon PS, an Olympus PS along with a Sony NEX-5 (for sale) and a NEX-7.

Based on my experience both Canon and Nikon have better camera and lens selections and if Nikon would give me their pro bodies and lenses (for free) I would go to the dark side.

My experience with Sony is they tend toward proprietary connections (flash) which means that I have to search long and hard to get something like a Radio Popper or Pocket Wizard. Also their lens array is not as complete as Canon or Nikon. Third party lens mfgs. do not make all their lenses in a Sony mount. My perception is that Sony is just not as complete of a line as Canon or Nikon while their prices are equal to or higher than Canon or Nikon. I've also seen some complaints as to life (shutter actuations) of Sony bodies on the web.

Depending on the Sony body you can edit Sony ARW files in ACR. Adobe seems to update ACR to read new iterations of CR2 or NEF quicker than ARW.

All that being said Sony makes some nice products and can be paired with some mighty fine lenses by Carl Zeiss. The best camera is the one you have with you and the equipment that fails is normally that which is located 6 inches behind the viewfinder.

Actually, with a fairly cheap adapter, you can put any flash or shoe accessory on a sony dslr. As for limits to lens selection and other accessories, only the very most specialized items might be hard to come by in a sony version. I'm not sure where you come up with the reliability issue-it is a non issue. As you may be aware the imaging chips in most nikon dslrs are made by sony. As a former retail photo equipment salesperson, I can tell you there is not a penny's worth of difference in the end results that you are able to attain among all of the brands of dslr. It comes down to your prejudices(primarily) going in and how it feels in your hands. For the record I doubt that any of us, from the most experienced pro to the rankest beginner, utilize more than a tiny percentage of the capabilities of our chosen camera.

It's true that Sony has a proprietary flash, but it's also true that everyone else has a propriety shoe as well. Canon flash will mount on a Nikon but you can't use it, same with Nikon and same with Sony. Why do people go looking for reasons to trash Sony (or anyone else) without the facts.

I would endorse what Flashgordonbrown said, there is no bad DSLR out there and they will all respond to good user input with very good images.

If you want real innovation with your camera, then Sony is the brand making all the waves at the moment. NEX cameras, RX-100, RX-1, Sony SLT, in partnership with Zeiss and offering excellent lenses and we now hear that Hasselblad are joining with Sony to use Sony technology and to adopt the "e" and a-mount. Interesting times.

The OP askes about the a77, this is a brilliant camera and in my prejudiced view (I have a900 and a77 and NEX-7) leaves the competition playing catch up. Not that it is streets ahead in IQ (it is better) but the on camera controls which make it easier for the user to achieve the required result are unmatched. I'm thinking principally of the WYSIWYG EVF which effectively means you never again will need to "chimp", histogram or level available in the EVF, focus peaking which highlights in focus areas and a "focus magnify" function for critical final focus tweaking.

I didn't choose Sony in that I come from Minolta roots and Sony was the inevitable progression from that, but now I am very pleased to be with Sony. Sony is not perfect but who is?