The only places where I have had rude TSA staff have been ATL (southern hospitality???), IAD (politics, enough said) and EWR (NY anyone?).
ORD, SEA, PDX, MCI, SFO, LAX (granted, not the Tom Bradley terminal)... never a problem. ONT had one problem because the TSA eejit screening me didn't mark my boarding pass as having screened me, which caused a massive row between TSA and the boarding agents (and me in the middle), delaying the flight. I've never been so embarrassed.
SSSS is NOT random. Ever. Not for foreign pax anyway. ALL foreign passport holders are s/screened on domestic flights in the US. I've grown used to it.
S.