I do the commute from the Burtonsville Park and Ride to downtown DC/Foggy Bottom area.
I work a 7 to 3:30 pm schedule, so it's not that bad. I don't have a problem with the MARC train, but I would then need to take the metro to my final spot. I loathe the metro!
And so I take the commuter bus. What I enjoy about the commuter bus is that you get to relax and even sleep a little. If you have a work schedule like mine, the bus goes by the schedule.
If you leave your job after 4om, you run the risk of the bus being anywhere from 5-20 min late. It's annoying when that happens.
So yes, the commute from Laurel to DC can be done either by driving, taking the metro from Greenbelt, taking the MARC from Laurel or Muirkirk and then taking the metro or just taking the commuter bus.