OK- so I know that the WiFi is not a "guaranteed" service, but please do not advertise something that NEVER WORKS! If I were needing to do homework or tend to other business, this would be a real issue for me. Not only did the WiFi not work on either of our trips from LAS LAX (and back) and after speaking with other passengers, this is a VERY frequent occurrence.
In terms of seating, unless you MUST be in the front of the bus for whatever reason, the general seating is actually a bit more spacious because not as many people sit in the rear of the bus! For people that have difficulty climbing stairs, I recommend choosing a seat on the bottom floor of the bus because the stairs are very steep. P.S. another note about reservations: the "table" on the website at the reserved seats is about the size of an airline tray table... not nearly the size that they advertise! They make it look like you are getting half of a card table! Not hardly. Also, when booking (if you choose to do so) keep in mind that they will make "comfort stops" regardless of whether the bus is on time or not. We were about 30 minutes behind on the way home and STILL stopped at a rest area for a 35-minute break. Boo!
I can't recommend Mega Bus and will be driving myself in the future if I need to make a day trip.