Megabus is a cheap way to get a direct bus to California. Sometimes I take it to Riverside or to Los Angeles and it gets there just about as fast as driving out in a car. I won't use Greyhound as they stop in several places (and some routes have "lunch stops" for bus routes that came from far away and through Vegas) which make it such a long ride and costs more.
Prices usually have been $20ish for one way. It used to be cheaper the last time I used it and now it seems to be steady at $29. Still better than a plane ticket to my moms area which was going to be $150 this trip vs the $59. A plane only saves me about 90 of time as I have to be there early then board even though the ride itself is just 1 hour. I try to nap or get my game on so it's not even a big deal.
Both trips I've gone on have been uneventful and fine so I'm happy with that trend continuing. Boring and no problems arising always would be great. Out of my trips only 1 did I need to sit next to someone as the bus was near capacity heading home to Vegas (it was close to a holiday weekend). Often I get the 2 seats to myself so I can stretch out.
Out of the 4 buses only 1 did not have power outlets. The WiFi seems to work, but cellphones can have trouble as you have to physically get it to connect to its webpage, but my iPad had no problem with connecting automatically to the webpage. It's not very fast, but it's better than nothing in the desert dead zones.
If you didn't pay to reserve a seat, I would try to be there early to select a seat. Of course there are your share of loud and obnoxious people so I generally try to seat far away from them. Also bring music/headphones just in case. I find normally the seats downstairs to have more quiet since they are often the reserved seats (with tables), popular with elderly and fewer seats.
I hope that it stays this way as I really don't mind the bus so long as my experiences stay uneventful and the prices don't creep up.