i have not ran it yet to notice a power difference from stock nor would i really know because i am having motor work done also. but the product fits well and boyesen designed their cage to work without any modification unlike v force you have to modify the rubber carb boot on most models.
The metal cage solves the problem with ethonol attacking the rubber on the stock and V force reeds, wich i have had problems with before. Thats basicly the only up side to these. They dont line up good at all with the carburators or the airbox, it will work but is a pain to install them. They also come with ports for a boost bottle wich my 04 600H0 skidoo doesnt have nor does anyone make one to fit, so they have to be plugged somehow. The sled does seem to run good with them and they do recomend jetting doun one size wich i had already done.