Have you tried to benchmark writing out a page with Go templates, vs GO producing a JSON API that prints out into static HTML pages with JQUERY/Handlebars? How many RPS can you get with either scenario? What is Time to First Paint and when does the page finish printing for the user?
Go templates are not particularly fast, but I would be astonished if the client-side way one that battle.
There are faster server-side template engines in go though. One approach I particularly like is https://github.com/bouk/statictemplate, which generates code from your standard go templates that makes them quite a bit faster.
