Sounds like a solid set up to me. As for future upgrades, just play with it and see what you feel you'd want to change. I didn't know anything about these when I got mine. I just kind of rebuilt it as I broke stuff, or as I found things to not suit my needs.
As for updates on my Axial, I just painted the body olive drab and have just been wheeling it. I really need a new battery though, tired of these dinosaur batteries..
Really digging the 4link though. Highly recommend it.
