I can't speak for the DNX408 personally but I can certainly speak for the DEX408 which is the electric version which runs a lot of the same parts and over a full summer and winter season I have only had to replace one rear arm cause the screw was to short holding the bottom shock position and pulled out arm and a plastic spur that lost a tooth.
Also I was running it kit standard other than a full set of springs and set anti-roll bars so i am unsure what is needed extra to make these things perform. I have run at club and national level like this.
I have also just upgraded to the DEX408v2 car and that is amazing a massive step up again.
What suits one might not suit another but the best way to see yourself is to actually try things for yourself.
__________________
|