With no status:
DL weird (got three of four legs of one set of flights)
US bad (missing a web bonus, all my credit-card miles, and only gave me direct credit when the second leg was canceled and I was forced to connect instead)
AC mixed (good on UA flights and Holiday Inn, off on Delta Hotels--but traced that to a hotel problem)
AA very good (on Wyndham hotels only--will report back on a flight I'm in the middle of)