Ive been using the Losi gun for several months and it works very well. All I have to do is spray a little WD40 on the trigger and it works perfect, no leaking yet either. You cant beat that for under 50 bucks. The only thing that concerns me about the proline gun is that it might get caught inside the body of a truggy due to the part on the tip. The losi gun can yeild very impressive pit stops. I have completed a pit stop for a buddy of mine with the losi gun and when his car was in and out with such a quickness that the guy standing next to me was so amazed that he commented "Now thats what I call a pit stop!" In the right hands the fuel gun can be lethal.