Great in a pinch! The girl that drove my two friends and I ditched us in Vegas and went home the day before we were supposed to leave. In a panic, we went to the Greyhound website and got tickets to Los Angeles for the next day and it only came out to $23/person (including tax)! That would have been around how much I would have had to pay that biatch for gas anyways!
I would recommend getting to the station early (within an hour before) because a line starts to form and if you are at the front of the line you have a better choice of seats. The bus made a lunch stop and a handful of other stops along the way to drop people off. It was generally on time to each stop, but we arrived 10 minutes early to Los Angeles!
When we were buying our tickets, the Express was sold out which was a bummer because the one we took was I think about 6 hours to Los Angeles, but the Express is over an hour shorter.
Nonetheless, I think it's a great deal and I might look into taking it to Vegas and back next time (Express of course!)