The good: The install was easy, little bit of silicone work, let it set 24hours and good to go. It replaces stock air intake and airbox above the paper filter only, airbox below filter stays intact and can be converted back at anytime if you break the new silicone seal. I have only tried this at high elevation so any peformance gains I could not comment on. Does a great job of keeping out dust and dirt, found no bleed through upon cleaning. I use no toil and filter skins, worked great for a couple hundred miles of dust.
The bad(ish): not impressed with the fit of the base plate tabs, lots of play in original tab slots, so silicone must be right and complete or you will have major problems, also a silicone failure means the whole plate is loose and major air gaps would occur. The intake noise is now quite loud and throaty. Sounds good, like a ducati, but can be annoying when accelerating around 4-5k rpm. Filter gets dirty quick and has direct airflow to it without the stock air intake routing. Needs to be cleaned often.
Overall, still a good purchase, if you are riding serious dirt and dont mind additional maintenace, you need this!