Plain old gulf wax
Works great
love the cleanliness of the drivetrain and how easy upkeep is
also love how long I can go between re-waxing (300-500 miles so far)
shifting and running the chain is buttery
not sure about saved watts, but I *think* I feel better power transfer. Probably placebo effect
not sure about making drivetrain last longer but the cleanliness supports the claims since dirt usually causes much of the component wear.
i like working on my bike and find chain waxing to help in many ways. Never going back to oil unless I ride in the rain alot