> Perhaps they are referring to how long it takes to propagate your changes in their “Global Edge Network” once actually deployed
Correct, global propagations happen in 300ms after deployment: https://vercel.com/changelog/faster-and-more-reliable-global.... You can try it out here if you would like: http://on-demand-isr.vercel.app
> The 20-30 seconds their own Next.js template takes to deploy.
Indeed, this is not where we want it to be. We want single digit second, or ideally sub-second deployments. We're actively working on making these faster.
> The only reference to Next.js Live
Being able to share feedback instantly on Vercel Preview Deployments through comments was the evolution of Next.js Live. This was for a few reasons. One, we wanted it to work with all frameworks, not just Next.js. And two, early customer feedback from the private beta told us customers wanted a tool that helped consolidate and bring feedback directly into the UI layer. Thus, comments were born (and we have more updates coming here in the future).
> it takes 9 seconds to generate a “production” build
We agree. This is why we're investing in Turbopack to speed up production builds: https://turbo.build/pack. We're also exploring other innovation in the bundler space that could help improve production build performance inside Next.js.