Obviously someone doesn't like that I like V Force. I would just like to say, that my preference of the V Force system over the Rad Valve, is completely opinion, not fact. I also believe that the power gains recieved from both systems are quite bike specific. I did like the Rad Valve, but I made the switch after learning more about the two parts. Both Systems are going to give you an improvement in power, one of them might be more, maybe not. However, with this hp gain comes other things. A pro rider from my area that owns his own shop, and is constantly building bikes. I asked him about getting a rad valve, and he told me to get the v force, because with the rad valve I would have to make drastic jetting changes, which isn't hard or anything, but it's a PITA. Secondly he told me that the rad valve would wear reeds out quicker, because it's metal as opposed to plastic. The vforce is nice, because it's a snap together design, and requires little to no jetting changes to notice a decent power increase. Hence The Vforce is more user friendly. Another thing is, the Rad Valve is presented pretty crapily, the boot looks like junk to me, and some valves have the same part number, as valves of completely different bikes. Now it's not that I'm lazy, and I absolutely love working on my bike, but unless the Rad Valve was handed to me, along with 8 main jets, a couple pilot jets, a few needles, and a few extra days in my life. I'm going with the old snap together bolt on power and ride. Yes, a KX500 is more powerful than my YZ250, but I would rather have the YZ250. I guess it's just my opinion. End Rant.