Well Frank, I will say that for having this camera for only a couple of weeks now that the one thing that has bothered me is the lack AF points towards the perimeter.
Coming from an a700 and always shooting in local AF I'm finding that I always cut off the feet when in portrait orientation with the a850.
The one double cross ( f/2.8 ) sensor is similar to the a700 but the a700 has 2 more AF points across a wider area of the viewfinder, better for full body portraits.
I think it's just going to take some getting used to. The one thing I have to remember is that I have a lot more room to crop.
Other then that, everything else about the a850 is all positive. I rarely shoot in burst so the 3FPS is not that important to me. I am very happy that I got one at such a great price.