i have been in the hobby for about 9 months and i started out with a brushed rustler. after a few months i got sick of how slow it went. so i the upgrade to the velenion system. and i have been very happy with it. however i have been only running the stock 7 cell nimh batteries. now once again i am looking for more speed. i m not sure if i should get a 5 series 8 cell nimh from traxxas or a lipo.