As you can see for yourself from most of the pictures on this web site that are taken with the Slt a77 and the few with the A700 the Sony cameras are as good as any. And indeed for those of you who maybe dont know, Sony manufacture the sensors for many other brands of camera. For instance Nikon and Pentax and also many smart phones. So Sony are up there with the big boys, but as with all cameras the sensor is only as good as the lens in front of it so bear this in mind when purchasing. You are far better off with a lower model camera and spending as much as possible on the finest quality lenses. Unfortunately... at the moment there are far more new ...second hand and old model lenses available for Canon and Nikon than any other. But dont let that put you off, some of the best pictures come from the most unlikely sources!
Sony SLT-A77 with Samyang 85mm f1.4 IF MC Lens(Manual focus)
SLT-A77 with Tamron SP AF 70-200mm F/2.8 Di LD IF Macro lens