Re: By the way, have you met Ms. Jackson?
I picked up the Ellefson Rust In Peace import 5-string a couple of years ago, and it's a nice bass. Compared to my 1990 Jackson Concert V Pro bass, I'd say the necks are similarly profiled, and the string spacing on the Ellefson is very narrow. The knobs are a bit scrunched together, though. Easy to fat-knuckle the neighboring knob unintentionally, like a crowded elevator.
I'd imagine the 4-string model is equally comfy as the Model 2B, since that's pretty much what they took the current designs from.