I have the Medieval TIP. Mine fit O.K. a little tweaking of hoses and all is well. I only paid ($99) so, I figured what the hell I'll give it a try. Darkstarmotorsports was also very good with customer service and dealing with me. I figure they all do the same job at whatever price you pay. You can argue about construction or which manufacturer is better but when all is said and done this one does the job. As far as actual HP gains, I don't know. Haven't seen any real dyno numbers on this part, I know that the air flow has to be better with the inlet pipe...