We recently upgraded to Bamboo 4.4.5, from I believe 3.4.3.
One thing I noticed is that there seems to be less flexibility in setting child plan relationships. I used to be able to change a child plan and make itself a child of another plan, without changing the parent plan. I could set this so the child plan would run asynchronously from the parent plan. Now, in 4.4.5, I have to edit the parent plan in order to have a child plan. This could be just a minor annoyance, as long as the functionality is still the same.
Where I'm really concerned is when I have multiple child plans. I would think that in the old Bamboo, I could define multiple child plans that would start asynchronously after the parent plan completes. I never tested that, but it seems logical.
Now, in 4.4.5, I have to define all of the child plans specifically in the parent, and they are listed in a specific order. There is no indication of whether these plans will run synchronously or asynchronously. I would assume that if it doesn't state it, it would be synchronously. That could be a big problem if someone needs the results from the second plan and the first plan takes a long time to complete, and the two plans are not dependent on each other.