We used JSPM in production for a year and a half. We had to switch back to Webpack because JSPM's bundles (even with HTTP2 enabled) were slowing down our time t

We used JSPM in production for a year and a half. We had to switch back to Webpack because JSPM's bundles (even with HTTP2 enabled) were slowing down our time to first render drastically. About an extra 2 seconds on 3g mobile compared to the same site with webpack. We're an edge case though, for most sites JSPM will work fine, and if it's currently working for you don't switch over. Switching over was a pain so I don't recommend switching unless you absolutely have to. I would not recommend using it for new projects though.