I do agree with Frank.
The Fazon can do in all of you´re conditions a good job.
For street + speed you better buy street tires, the others will ballooning on 6S.
But take care, the Nero / Fazon on 6S can be a beast! (But afterwards you have a big grind on you're face!)
For running dirt an grass, I recommend just 4S because of the force to the drive train when the tires have a good grip.
Let me remember you, the Fazon is a truck which weight is around 6Kg without battery´s. I will be heavier to control then the lighter Kraton.
My colleague had yesterday done an front flip just by breaking hard with a locked center diff... (Ok it was dark outside and we just had the light of the trucks)
But he flipped just in the position roof onto the asphalt and sliding. Nothing broken but ugly scratches on the body and the light canister on top..
Ahem, just one more suggestion.. Try out different spring settings. On street it will be better to lower the chassis and put a bit stiffer oil into the shocks. The Fazon / Nero has no sway bar. If you are an good handyman, maybe you can use the holes in the lower arms to mount such. Normally the holes are for mud guards. I don´t know whats up with the diff housing and if it is possible to mount a sway bar on it.
Regards,
lonee