How does Zube do in terms of performance when loading up?

One of my biggest issues with Waffle or Zenhub is that loading them up is often a long wait- Zenhub can be 3-4 seconds(and often is just incorrect in labels/assignments), and Waffle could be upwards of 15 seconds.

Does this do any caching on Zube's side and then real-time update it as it goes, or am I in for a long wait again regardless?