It has potential. The I-15 from Vegas to LA was a nightmare yesterday.
Not for $200 round trip. $400 for a couple. Makes even less sense if you are going to Vegas with a group of friends.
Driving to Fullerton to catch the train and pay that much for a train ticket? No thanks.
Why drive to Fullerton when you can take the train to get there?
I would never drive back to Los Angeles from Vegas after a major holiday. If faced with that sort of traffic, I would have shun-piked through Kelso and 29 Palms, and maybe even taken the Palms to Pines Highway.