The vents do make a positive difference IMO. Yeah, when it's 100° outside that's what you're getting, but at least there's some airflow moving throw the footbox which keeps it from turning into a complete oven. I hardly ever use (like never) the blowers. In the phot you can see the blast gate on the passenger foot box and the blower on the outside of the frame. The incoming air gets picked up from the brake duct openings. When you're moving you get a 40 or 50MPH breeze depending on how fast you're going. When stopped, you're either picking up pavement heat or the heat from the guy in front which is why I rarely use the fans. But this is Southern California, in an area with higher humidity you may find the fans are a blessing. I used Cobra Earl's kit including his double brake duct vents. It comes with everything. Wiriing, switches, rivets, instructions, etc. Earl currently has two types of ducting available now, although mine came with a real strong black flex tubing which I like because it doesnt call attention to it.
HTH
Frank