Template Extensions vs ES2015

So, after 12+ months of analyzing, experimenting, and research, I finally have the inheritance class structure that I want to implement for a number production apps I’m working on. I know I need to use either aldeed:template-extensions or grigio:babel. But I’m not sure if they’re truly equivalent, or if there are gotchya differences.

Mind if I cash in some karma and ask for a bit of help here? Has anybody used both and able to weigh in on the pros/cons of each? ES2015 seems like it’s maybe the better way to go. But template-extensions seems more mature and stable. Will ES2015 class extensions actually provide the same functionality as what’s implemented in template-extensions? Or are there gaps that will need to be filled in?

Curious to know other people’s experiences with template-extensions, ES2105, and even perhaps blaze-components.
Thx,
Abigail