Done both...
Great cargo haulers...
And as for the Boom effect, true, except Copperheads have an area effect built in... each round does 20 points in the hex, but does 10 the surrounding hexes as well... times 5 per ton times 10 extra tons ( Cargo of BFFL ) = 500 extra points each of the six surrounding impact hex, that should get some head turnings at the table!
TT