Excellent idea, perfect. I'd say no weapons, but massively huge hold, at least twice as big as the L train's. Also should be reasonably sized... for example, if it's going to have a hold twice as big as the L train's, then I'd say it should hold 12 cargo pods. Also note that if you can base it on the L train, each pod holds about 750 cargo. Also, insanely slow turning. Maybe the agility of a BC, or even an agile BS.