I've had K&N and Volant and like things about both of them, and disliked some thing about them! I have never had any issues with oiled filters and really don't think they cause any issues. But with the 2 systems I had I would buy a Volant again, I just like the enclosed filter box. Not that the K&N was bad but it is an open element in your engine bay.
2002 Silverado 2500HD LB7 CCSB LT
EFI Live by Rob at ATP, Edge CTS Insight DSP 5 control, S&B CAI, PPE boost valve, Pro Fab AIH, AirDog II 165, PPE WIF sensor delete plug, 5" stainless exhaust, Cognito braces & HD tie rods, H2's 315/70 R17 BFG's
2004 Tahoe LT
2006 Silverado Z71 LS
1971 Chevy C10