>>12290548legit answer.
My PI is brilliant (defending in a month boys, wish me luck). She runs circles around some of the other staff easily.
Her teaching is abysmal because she just wants to get back to the lab. Looks at slides from a year ago, updates like 2 of them, gives the same lecture as before for an hour or 2, back to lab.
Most PIs shit on undergrads from what I've seen though, since most are premed who screech about not being given free A's and the others are stoner dropouts who care more about #collegelife than actually doing good work (we screen our undergrads and have lucked out well, but still its 50/50 if a new undergrad is going to suck or not)