This line operates the commuter buses from the Baltimore area to DC and suburban DC areas. On the positive side, the ride is more comfortable and there are fewer stops than a Metro bus.
The down side is the IQ of the drivers varies. Some have the wit to count how many people have boarded and will not take on more riders if they don't have a seat for them, but some don't care so you'll end up standing the whole time, even if one is disabled (it's not always a sure thing that they'll enforce handicapped seating).
Some drivers are fond of "jack rabbits" starts so anyone in the aisle will fall unless they are gripping the back of someone's seat. (And if you fall, they'll ignore you, not even asking if you're OK.) Some are fun, lively people who sing along to opera playing on their radios. It's sort of like Forrest Gump and his chocolates, but the bad drivers outnumber the good ones, in my experience.
If you want a window seat, it's best to be on either end of the commute, or take the bus late in the PM run or early in the AM. Also, traffic can double the estimated time in the schedule, so resign yourself to a lot of waiting for the bus to show up. (Particularly if it's freezing rain out, you'll wait half an hour or more between buses.) And when schools are 2 hours late, they don't adjust their schedule, and buses only run once every few hours after 8 AM or so.
Cost varies (for example, they charge $3.50 for service from Burtonsville to Silver Spring; $4.25 from Columbia to DC). If you buy a 10 trip ticket, there's a 10% discount. They also sell monthly passes at the MTA site that work out to another 10-15% discount.
I rate this company low because their drivers are so bad but if you really hate driving to work, and public transportation is too creepy or inconvenient, you might try it. I wish it were better. read more