i am not familiar with SD United but there was a LA united that was pretty shady. From my understanding they took over name from original United EMS from 80-90's. Beware if they are owned by guy named Rodney. Or if they have a supervisor named Kevin who insist to go by rank of Captain. They had a thing where they have "ride" a day which just them getting free work with shifts they cant fill. They were just shut down not to long ago in LACo. They might have moved on to a less restricted county to remain in business as some other LA companies have done.