Fact: make your own. It'll be less expensive, and probably of similar quality.

Opinion: Unless you play polo, or do a time trial, or maybe actually take it to the track, then don't bother. For polo, it serves a functional purpose to save your spokes from balls and mallets. Beyond that, the gain is purely speculative. (Without wind-tunnel or otherwise scientific testing, there is absolutely no gauge of how aero the modification is, aside from how the bike feels/what kind of times you run. and even that may be due to psychology/some kind of placebo effect)

on the street, it won't matter all that much, it'll make your ride heavier, and crosswinds will make your bike buck around under you (especially if you disc the front)