e-mike, the stock Mamba Max heatsink just fell off one day, so rather than glue the stocker back on I installed a PC northbridge heatsink I had that looked like it would keep the ESC cooler (more surface area). There is a fan attached on the far end of the heatsink (on the rear side), it works very well and the Mamba runs very cool.
e-mike, my buggies are on the heavy side because I over build for durability. The motor mount, servo brackets, battery tray are heavy duty. I drive my buggies long and hard and I don't want things falling apart. My Kyosho Kanai weights 8lbs 9oz with a 4s lipo, the CEN buggy is a little lighter at 8lbs 3oz with a 4s lipo mainly because it doesn't have any of the mechanical brake parts (rotor, pads, servo, etc.).