I have been running the 8 rib 2.7 rip with my overdriven Cog setup for over 2 years. They work VERY WELL!
There are many TBSS guys running them on 6 rib DD's and have great luck....
We have been at the maggie game for a wile longer in the trailblazer world! It is nice to have a place like here, with LOTS of maggie talk!