I installed the FW 0.4 on my babyjet. Upgrade procedure was painless, really.

Findings:
-I still only have 3 working dies
-BFGMiner works like before
-CGMiner doesn't find a device anymore (tried 3.11, 3.12.3 and 4.0 w/ zadig)

Hashrate seems actually a bit lower than 0.2. Might try that 0.3 release tomorrow.