I have used the Tightwad (.660) and the H-13 (.662) with H-13 7s. The H-13 choke edges out the Tightwad in my shotgun (within 3% of each other). I have not shot the Truglo Gobble Stopper choke, but that is because of the choke diameter (.665). The .660 diameter tends to average 10% denser patterns than the .665 diameter for me.
With H-13 6's, I only see a 2% increase in pattern density using the .660 constriction vs. the .665.
As long as we are talking about Rem chokes, I also ran some H-13 7s through a .670 choke just to see what would happen. The pattern density drops off about 25% as compared to the .660 diameter chokes.