Do a search on this site and you will find plenty of hard data. The PV does yield a performance gain on the dyno as well as a difference in sound. I do not believe you will gain much power with a cone filter or with the removal of the elbow. Intake sounds may increase, which can be misleading, but a naturally aspirated motor is essentially a fixed displacement air pump. It can only pump as much air as it displaces. Realistically, you'd be lucky to see a 5 HP gain by the most optimistic estimate with intake mods. Force induction is the only way to go to gain significant power without changing the engine's internals (ie altering compression ratio etc.).