Gapless were invented for dirt cars that ate rings- They do offer impressive leak down test results but on the dyno I have never seen the HP gain. Correctly filed rings with a ductile top ring is the standard that has won most races.
For whatever reason the leak down that looks fantastic does not seem to convert to more power--because of ring flutter at higher RPM or what I don't know but gapless rings are not magic or they would be in every engine built
You have to remember that KB did back to back dyno test while working on the proper gap for their hyper pistons and the top gap had to exceed something like .055 before they could see a HP drop--Now..thats their tale but many shops agree, keep rings from butting and make sure fresh cylinders are clean and you have done all that you can in that dept.