Advice on a telephoto for Sony A77 and A99

What about the new G 300 mm f:2.8 II with enhanced optics and much faster focus motor? If you were pleased with the focal length of your Minolta lens the new one would be a nice replacement. Personally I really enjoy my G 70-400 mm, but at f:5.6 at the long end it isn't the brightest lens. Crisp and sharp wide open though, and light enough to carry around all the day. Focus is pretty fast, so with 4x improvement and even higher contrast the new lens would be really nice, I think!