According to
this LA Times story, it's going reasonably smoothly so far, with some inevitable confusion among incoming passengers. I love this bit: "The lack of honking and idling cars [on the arrivals level] created an eerily quiet atmosphere on the once-chaotic sidewalks next to the terminal." I've often wondered how many arriving tourists considered going back into the terminal to catch a flight home, their hearts sinking as their first experience of Los Angeles was a stinky, noisy, seemingly interminable wait for a shuttle in the claustrophobic arrivals cave.
I'll be interested to hear FTers' experiences with the new system.