As I recall I had issues getting the OS3.9 Boing Bag 2 installed (I had to find a missing library first or something), and so I was cautious about installing Boing Bags 3 & 4. As long as my software works I really not bothered that OS3.9 is no longer developed. I definitely not going back to Workbench 3.1, that would be insane! My only guess is that this Workbench 3.1 development is so that Hyperion can negotiate a bundling deal with the Apollo Team for the upcoming Vampire V4 standalone machine otherwise what's the point?