I have used the Losi gun (it was rezenclowd3's) and if pointed down it didnt leak at all as long as no fuel made it into the vents when filled and it wasnt leaned forward, yes it does leak if used wrong but with his at least there was no leaking when used correctly, it was a very nice gun, I watched somebody next to me use a pro-line gun when using the Losi gun and it looked to be a tiny bit faster but not worth the $20.