I had the K&N intake on my 2015 Trail for a couple weeks. I thought the sound under WOT was cool, though a bit louder than I would have liked. I also agree that it sure feels like there is more power above 4k rpm.
I pulled it off and sold it for a couple reasons
1) I'm super sensitive to low-end torque (or the lack thereof) in this truck. It has to downshift when a little headwind hits it on the freeway. it's kind of pathetic in that sense. With the K&N, I could sense near zero change in low end torque, and I know enough about intakes (those heimholz resonators are there for more than just sound deadening) to know that it's quite likely we're *losing* low end torque with the K&N. Especially because those resonators are there to improve torque. I haven't seen any dyno tests of the intake that go below 3krpm. I'm not sure it would even be possible to reliably get a reading down to 1.5k with our automatic transmission?
2) Because of the need to downshift to make anything happen, I'd be cruising along quietly, need a bit more power, and then be roaring loudly at the top of the tach (as it kicked down). For me, this dynamic felt a bit juvenile (i'm old) and just reinforced how lazy the truck is down low. That you need to beat the crap out of it to get power. Now, it doesn't help that the engine is just noise, not music. Turning it up is just louder noise (IMO).
/curmudgeon