Scripts have been made more robust, and I switched to exec reading a local variable called output_result. Whilst this is likely to change later on I've tested it a few ways with some different maths and formatting problems and it appears to be stable to me.
I would say all core features are stable in this release - the next release will be refactoring, then creating the add-on system.
If you are looking for a stable version to stick too until another major release, this is the best choice!