Sounds like were are talking about 3 things, open, close, and fore/aft. Fore and aft has to do with the surfaces rubbing one another. Naturally the harder those surfaces the less friction there will be. Also a little extra clearance helps too. For bare stainless the Bordens are the hardest and also smoothest in my experience. Nitrided actions are even better. The old vipers are great, anodized on chrome. The close function is all about ignition timing, Bordens are the only action timed from the factory. Open is a function of cocking can helix angle and spring force. Bordens open stiffer as they have a steeper can angle (necessary to properly time the ignition) and also the stiffest spring out of all others. Jim has a new spring that we are testing that will help, but it has to be proven to not effect accuracy first. So it comes down to personal preference. My first choice are Borden actions. Second are the Kelblys and Pierce. Pierce is building me a BR action, stainless body, rb,lp,re, and heavy tang. We'll be giving it away in August for the championship match, as well as a BRM.