The demo of the store there didn't feel any fast to me. Been working on Rails-backed ecommerce that's feels faster than this.

I am 90% sure the SPA ppl believe that as soon as 'first render' is detected they are done performance wise. I mean, waiting 20s looking at a grey screen with a poorly rendered spinner that renders in 100ms is obviously much better UX than waiting 0.5s for a form to render. (Looking at you AWS!) /s

So sorry to hear that! I'll take a look at it. Thanks for the feedback