Judo Ne Waza from my experience is very strong, aggresive and focuses on the top game. There isn't as much emphasis upon flowwing from submission to submission as you aren't allowed enough time on the ground. However, submissions are applied really quickly and aggressively.
BJJ ground work in my oppinion is more technical and is often more relaxed. You have loads of time to set up submissions and apply your stratergy from the ground.
I actually think that Judo fills allot of the gaps that are in Jiu Jitsu and vice versa. So train both if you can.
Bobby Rich gives me nightmares..........