@mulveling .. +1 on this:
"Whatever cleaning regimen you choose, full stylus & cantilever brushing should be a part of it."
Sometime over the last week my vinyl lost some of the magic. As part of this Onzow gunk thread, I've been scrutinizing my cartridge with 8X magnification. From both sides, from the front, from the back. Seems a small hair or fiber wrapped itself around the cantilever and was acting as a leash on the motion. Very carefully unwrapped it since just a back to front brushing wouldn't dislodge it. Adding regular magnified cartridge inspection to my routine.