So I took the Megabus from Baltimore to DC. It was great! The bus was the same as a regular coach bus, and stated that it had WiFi (I couldn't check though because I didn't want to cart my laptop). The bus up was about half full ( ie everyone except for a few had 2 seats to themselves) The bus back home was 3/4 full...

we made good time both ways and I will definitely use them again.

Also, on the way up I saw a few BoltBuses coming back the opposite way... turns out its the same type deal as Megabus. A couple in front of me night 1 at MSG had taken the BoltBus from DC ( for $1!) and they said it was great... and half full.