Performance is extremely important. I say that because we use Jestor every day here, and if it's a bit slow we immediately try to understand why and how to make it faster. About templates, did you use it straight from the website or by installing into an account? I'm asking so I can check with the team and solve it asap!
I was installing it from the website just by clicking on the template. The installation was not what bothered me but the overall responsiveness and loading time. Iām based in Berlin, might have been the roundtrip time.