My new dashboard filled with wonderful gadgets takes about 4 times longer to render as the old 3.13 dashboard, which is annoying, but acceptable.

What is not usable is none of this data is cached, once you choose an issue, if you click back to return to the dashboard, you have to wait the entire time again. I only have 3 panes on my dashboard, I can't imagine how much this will annoy someone with a complicated dashboard layout