Hey I run the K&N Gen II, on all of my vehicles and really have enjoyed them, and have had no problems with them. My friend just bought 05 Chevy 5.3, and he bought one of those Vararams kits for his and I was really impressed with its performance. He also has ran the K&N Gen II and says he noticed alot bigger difference with the Vararam. So I can't bash Vararam that my friends truck works really good. But I can tell you from Experience I like the K&N Gen II.
2002 Red Chevy RCSS (engine mods)- 05 5.3L, Procharger P-1SC 9lb.pulley, 80mm BBK TB, TB By-Pass, 38lb. Inj., AlkyControl Meth Kit, ASM L/T's, Magnaflow X-pipe, Borla's, FLT Level 5 4L65e, PI 3000 Stall, B&M Tranny Cooler, 3:73's, G-80, E-Fans, 160' Thermo. Custom Built Intake with K&N. WideBand 02 Sensor, DIXIE TUNED.