They are ok
I have one on my 97. I noticed that it does change the aerodynamics of the hood area. From what I can tell with "love bug season" it works good but does not get every one. I can say at least an 80% decrease in bugs on the the windshield. A big change that I have noticed is that with the manual side mirrors, they tend to shake alot more. I guess its from the air displacing more to the sides. But my fuel milage has appeared to stay the same.