I've been trying out FB6 and really like it so far -- especially the VS.NET Solution Iterator!
I think there is a small bug with the before/after action event scripts. I usually use JavaScript for my before/after action scripts. I'm frequently finding that the selected scripting language has been reverted back to VBScript, causing the scripts (and thus the actions) to fail. I believe the language selection is somehow reverted if I modify the action in any way, or possibly when I modify a global script that is called from the action script.
If I just change the language back to JavaScript and it works fine. I don't recall this ever happening in FB5.
-Mike