My opinion:
No on the K&N - I've tried them on cars and bikes - they have been replaced !!
No on the Aero 5050 !! I got talked into one (ok - I'm a sucker for more HP) at Brazel's RV, on a trip up north in 2006. Did not notice any gain in performance but it did make my RV sound like the biggest, loudest Honda rice-rocket in the world. It had a high pitch and was embarrassing to go through tunnels and under bridges !! Yuck
I replaced the Aero with a straight through Magna-flow and now have a nice deep sound that makes me smile. When I smile, I can feel a slight increase in HP ! lol