The Big Rock will be a little different than what you currently have, but i would personally go for a different type of RC. And I'm with the others and prefer to build them rather than buy them RTR.
I have just about every type of surface RC except a Short Course Truck. I think I want to build the Traxxas Ultimate Desert Racer after we get caught up on a few projects.
Other than that, I am trying to gather and collect all the Kyosho Legendary kits like the Javelin, Turbo Optima, Beetle, etc. They are some of the best made kits out there, and the price isn't bad for what you get.
We also recently got into drag racing with the DR10 Tunedpipe gave my boy. I built a Traxxas Slash into a drag car and can't wait til the weather warms up so we can do some racing. I didn't think I would like drag racing RC cars, but they are really a blast.
Hope this helps.