No problem, thanks for taking the time to reply. With JSPM The loading times are slow even for bundled apps. From looking at the timeline profile it is mostly

No problem, thanks for taking the time to reply. With JSPM The loading times are slow even for bundled apps. From looking at the timeline profile it is mostly JS execution time. The `else` keyword really does work well in Vue, you should really consider it. It's just that a lot of time we have if.bind='stuff' immediately followed by if.bind='!stuff', and 'stuff' can get complicated. And for the Object.observe, I do not know how Vue does it but it doesn't have those issues, maybe you can use a similar solution ? Anyway I'll file bugs and we can continue the discussion on the tracker.