The version of SAN-OS I have been practicing with is 3.3(5), since that is the latest in the 3.3 train, and likely to have the least amount of bugs. There are some additional bugs I have encountered however. There is a bug, which is not available to view publically (I am not sure why), CSCsr44223. This bug basically makes it so that even if you have an eval license for Fabric Manager Server (under grace period), the switch does not respond properly to license requests for Fabric Manager Server. The result, is that you can’t use FMS with 3.3(5) unless you have a permanent license. I am not sure when this bug gets fixed, as the bug ID is marked private.
Another issue, is that even if you have a permanent license, FMS still will not work with Fabric Manager 3.3(5). There is also a bug in FM 3.3(5) that does not properly request the license. So you have to run FM 4.2, which is downward compatible so is not an issue.
For now I am continuing to run 3.3(5). I may however, drop back to 3.2, which according to the Cisco CCIE website is what is tested on in the lab. The only reason I do not run 3.2 is because it has a nasty SDV bug CSCsu72092. However, I am starting to weigh the odds to see if its more of a PITA to be running 3.3(5) which comes with its own set of bugs and strange issues.
I hope Cisco releases at least one more update to 3.3 so that we can get some of these things fixed.