Think for cz users the choice may b easier. Do u need the range n if the f-stop is an issue. Tamron essentially asking if ssm n 1mm wider is necessary.
Since you have the Tamron 17-50 f/2.8, when the A77 comes out get the body only and try. If it is ok, use it. If not, sell it and get the other lenses.
Or you can get the A77 with the 16-50 f/2.8 set. Try it first, sell whatever that is extra. Let me know if you are selling the Sony 16-50 f/2.8.:angel:
You can drop by my house to try the CZ 16-80.