My main was becoming a problem, particularly going up. Found a major problem with the main halyard sheave. The sheave is aluminum with a bronze bushing riding on a stainless pin. The bushing had deformed and extruded past the sides of the sheave and was binding in the masthead - after removing the pin, I need two screwdrivers to pry the sheave out of the masthead! Replaced the bushing ($0.49) and the problem disappeared.
As for lube of the track, I like the spray silicone. Also works wonders for the tracks of Anderson casement windows. Don't use an oil or grease - it will just collect dirt.