Must they be cleaned every 3 to 5k? If yes, that's a sure no for me. I want as fuss free as possible.. so stock filter I guess.Yes the AFE dry version is actually dry. I have been running two of them in my 981 for a few years now (981 has 2 since both intakes are functional). I remove them every 3-5K and soak them down with a special cleaning agent they sell. Looks similar to "Simple Green" cleaner if you are familiar with than name.
You wait 5 minutes and then rinse them out and let dry. I dont know about the 987, but they are direct bolt on fit to my 981 using provided fine thread bolts that go into brass threads within the filter base rather than the factory self tapping screws that go into the 981s plastic filter base
I have PSE so I hear no difference in intake noise, nor feel any difference in power. I use them simply because they are a reusable service item and will pay for themselves over time