Upload & Sell: Off
I'm using the Mirex adapter with a Sony a850. It shouldn't be any different on the a99. I already owned a set of Mamiya lenses, so I went with that option. I also use the ZA 24-70 f/2.8 zoom and find that the Mamiya lenses aren't quite at the same level, but they're not far off. The combination is class-leading cheap, though, if you don't mind the wait for the adapter to ship to you. I primarily use the 35mm, 55mm, and 80mm Mamiya lenses. All are good enough that focusing errors are more likely to be a problem than lens flaws. I own the Mamiya 45mm as well, but prefer the 35/55 options to carry instead.