Here is a sample of the A77 in 12fps mode. I didn't bother playing with the other settings as I just picked up the camera and basically just press the shutter because the excitement got the better of me that day.
I managed to get 18-20 shots in less than half-a-second. I did intentionally stop shooting after that as I was just checking the EVF lag and to me it is just like a 'blink of an eye'. The shutter sound is very muted as there are no slapping mirrors to add the extra noise.
A77 12fps Mode - Flick Gallery
The 12fps mode in the A77 is a dial setting meaning you don't have to go the menu system. I really need to test it again properly as I want to see what it does on the ISO, aperture and the AF-points it activates. I am assuming it is on Wide but I would definitely prefer if I can select the focus point during the 12fps mode.