The newer ring packs are awesome but as mentioned it requires some very good modern machine work, and the new ring packs are not cheap either $300 and up.

After the last 3 builds being with the .043 .043 3mm rings im doing a std. 1/16 std. tension the drag is almost bothersome, with the thin ring packs and tight fitting pistons I could turn the assembly by hand on the crank snout easily.