The Super Nitro is bigger than the RS4 3 EVO. I think that cost wise the EVO will be to your liking. Aftermarket support I would think to be bigger since it is the more common choice.
i dont know, but personally i dont like it because, you go through one way bearings fast. you have to charge it every time you run out of juice, and you have to carry it around.
why do you overlook the .18ss rs4? i like my evo but i would give it up for the .18 i swapped out my rs4 evos engine the rotostart batteries die fast you wil need to but a high life battery.
The Rotostarts break due to over usage when hydrolocked. Just like a Pullstart when hydolocked, the mill needs to be cleared out.
The 18ss looks really cool but it alldepends on what you are looking to use it for. The 18 is not race legal and there more 12's that will stomp the 18ss.