DC United before the trade: 21 points/17 games = 1.24pts/gm
DC United after the trade: 25 points/16 games = 1.56pts/gm
If you take out the first four games (getting acclimated), they have earned 1.75pts/gm since the Sam trade (.5pts/gm in July, 1.8pts/gm in August, 1.6pts/gm in September, 3pts/gm in October). Obviously their jump is not all a result of adding Sam, but he has been a big part.
Conversely, RB has gone from 1.28pts/gm before the Sam trade to 2.07pts/gm in the games since. Sam departure has definitely not hurt us and it was probably smart to part with an over 30, obviously declining player while someone was willing to give us something in return. That said, I think we could have still played at a 2pts/gm pace with Sam on the bench or splitting time with Grella (who has not been great since Sam left).
Not arguing against the trade or saying the trade hurt us, just that the trade helped DC a lot this season. Ignoring all future elements of the trade, would you rather face DC with Sam on their wing or DC with Sam on our bench?