i'm so very pleased with this beast,went off of all the reviews and video and pieced mine together with (2) 4s 5000 mah lipos, stronger steering servo for back-up,but after running mine; i'm happy to say that the stock servo does a great job. you have to keep your eyes focused on this rocket becasuse it's just that fast. i love this over the nitro because there's far less aggevation due to always tuning the nitro's and its far $cheaper$ to run.I get 45 min. per 4s out of the 2 i've gottten. Thanks, redland,ca.(hobby people) for making this a wonderful buying experience for me.