As you probably know Azure Stack is currently in TP2 and performance of the portal is noticeably better than TP1. If the portal is sluggish for some reason, there is a way to check the portal load time of the different blades.
To investigate this, you can use the following key combination: CTRL-ALT-D.
Pressing CTRL-ALT-D again will remove the portal load information.
While checking for other key combinations, I also found CTRL-ALT-A which gives you a list of versions of various Azure Stack components.
If you fine any others, please let me know!