I put it to the pokertracker test.

Semi-Loose Ags averaged win rates of 10.4/bb
TAG averaged 5.6/bb

The key is to play slightly tighter that your opponents.

NL 10 36% VPIP
NL 25 26% VPIP
NL 50 24% VPIP

At these levels LAGGY's Rule. I wonder how they would do at much higher tighter limits? Anyone have VPIP % on NL 200 or higher?