It is a heavy oil ball. It's very rolly. With his layout it's going to be even more rolly. I personally don't think that it's ever going to SNAP like you're looking for. I made the mistake of drilling my first one 65x4.75x60, and it's so smooth I can't move in and wheel it. Maybe if I drilled the next one 45x4x30 and polished the snot out of it I could get it to snap, but that's not what the Train series is about.
You want more back end, look at the Freight Train instead.