I picked up the Sony 75-300 to try it out after getting frustrated with the Sigma 400 5.6. Some people have had good results, but tests made the lens seem horrid. Anyway, it blew the 400mm out of the water. Here's a few random shots from the feeder to test the lens, nothing meant to be serious. My favorite part is that bokeh... sweet.
All are straight from the camera with only resizing, no sharpening, levels, etc.
The mockingbird shots are at ISO 800, which have softened the image a little, but you will notice there is no excessive noise as rumored from the Sony Alpha.
Your thoughts greatly appreciated.