well if you can afford the (1/8 tekin system) sure i like castle i havent tried it on the 1/8 scale yet but i am but i did run a (castle 5700kv) on my 1/18 scale and liked it its not the smoothest i whould say though lol.
i dont know about the, (tekin 1/8 system) though i know when they first came out in 09 i had a guy who i raced with that had tons of problems with it shuting off and i think burning up and some others that ran them had no problems at all.
the only thing thats weird, with the castle brushless i dont know if its just with their cheaper brushless systems but the one for the 1/18 scale loses its settings sometimes for some odd reason weird.