Thanks sgtlt,
I have been running around the forums and the servo concern is always at the top from what I can see. Then followed by tires, really I see them listed as 1A and 1B on most posts. I also see people talking about suspension upgrades, gear box, etc.
My local shop owner did say that the B4.2 RTR is very competitive in this class out of the box. I just want to be sure to upgrade the MUSTs first while I have the "extra" cash on hand. Thinking about getting a decent set of tools as well.