Does it work. YES!!!
I built my own after that company would not bother to answer their e mail. I made a pattern from the stock cover using the copy machine at work. The midrange power feels quite a bit stronger with a harder "hit"
It is easy to change back if you dont like the mod. I used some scrap 1/8 inch aluminum. I polished it up and clear coated it. I say go for it. I have a friend who rode the bike and felt the same way about it.
The bike is not as easy to ride on tight trails as it was before. Still, no big deal. The cover is held on by a few bolts.