This slipped out under our radar (27th Feb), probably as part of the expansion of the line to include the Quattro Enzo etc.
The main reason for mentioning it, is that 1.6 has a firmware upgrade for existing Quattro aids. It takes under 10mins and is wireless. Might be handy if you are experiencing any connectivity issues.
You can force your Aventa to look for the upgrade using the Menu option on the far right of the red bar in the main fitting screen.