Well, it has slow thrust speed, though it's more maneuverable than a C-Tran. I probably would use it myself, except it lacks a CM dropper.
I'm not saying that the Whale needs more cargo, but the Leviathan Supertanker could be a 2nd generation version. Much bigger, with much more cargo, but still no guns, and still not the toughest ship around. And much less maneuverable.