This is a superb camera for the serious amateur. The definition is outstanding. I have had some excellent A3 enlargements from my old A100 but the A850 offers much higher quality. With its 24 Mp sensor that isn't a surprise but comparing the results the A850 still produces a 'Wow'.
The controls are easy to use and the Function button offers quick access to them. The camera is relatively heavy and won't fit in your pocket but this is a camera for serious users. A professional would doubtless want access to the greater range of lenses offered by Canon and Nikon but their cameras come at a much higher price.
My old Minolta lenses are compatible with the A850 which is a bonus. The old 28-80mm Minolta 505 lens produces excellent results with the A850 and gives the new Zeiss 24-70 mm lens a run for its money. The Zeiss lens does have better contrast at higher magnifications though.