Hi, bit of a noob on this site but will add my comments with regards the new a77.
My past Sony cameras have been the a200 a350 and currently the a850.
I have tried a direct comparison, handling wise, the 850 with the a77 both with my Sigma 24-70 f2.8 bells and whistles lens.
The a77 handles better in my opinion, as the 850 is one hell of a heavy camera though superb in its construction.
I compare it to an old rolls royce as opposed to the a77 being a new generation bently both superbly made though the 850 will last longer and stand more stresses and strains if you are a pro.
With regards to buffer size etc using compressed raw on the 850 you only have 9 shots before the buffer is full so the a77 is acually better in that respect! Oh I have one on order and the a850 is up for sale along with the Sigma lens £1300 the lot including remote commander and book
Cheers from geordieland, newcastle upon tyne, uk