Actually, those have been great (and thank you for making them)! We had an outage during beta because somebody forgot to wrap an array comprehension assignment (CoffeeScript) and we didn't test right. Backbone has been really good, and while we had some complaints, I think many have been resolved in more recent versions - we're on something ancient.
Isn't that one of the major drawbacks of using a bleeding edge Tech Stack? Albeit mitigated by choosing to use code that is easy to comprehend/maintain (like backbone!)
What do you think you will do? E.g. With backbone: Merge up, status quo -- maintain your branch, change libraries, or something else?
Agreed, it made some necessary, non-backward-compatible changes as a result of being such a young project. I think it is likely that we will upgrade to a newer version soon.