Nice ride, clean too especially for being used. I would recommend a stronger steering servo though. That JR Z590 makes for a great throttle servo, but won't last trying to guide the 8.5lb missle you got there. You could endlessly burn out midrange servos for 40 bucks a pop in the steering position, or buy one good one to last the life of your buggy for 80-100.
When you have the spare coin, go for a unit that hits these points (most important to least):
-coreless motor
-metal gears
-150oz or greater torque
-.15 or faster transit
There are units from Airtronics (94358, 94359), Ace (DS1313, DS1013, DS1015), Hitec (985, 5985, or 5997), KO Propo (2344, 2364, 2366) all are coreless, sub .13 transit times, and 170+ torque. I have seen most of these for around $80.00 on e-bay, but you have to wait for a deal on some of them. I personally have the KO Propo PDS2344FET, and love it. Rediculously fast, holds its line well, and re-centers well too.
I smoked two JR Z270s (shouldn't have even tried with all plastic gears), a
Hitec 645MG, a JR Z590, and a Blue Bird 660MG before I got my first good steering servo. It is definitely worth the upgrade.