Playlists: Discover Weekly tends to result in ~3-5 (new to me) musicians/week that I hadn't heard of that I would actually listen to. That's a pretty high ratio IMO.
Release Radar tends to result in ~1 (new to me)/week. Granted, it's supposedly mostly ones I listen to, but still has several I've never heard of.
Daily Mix 1-6 are a mixed bag and sometimes result in something new, but mostly just things I like (and may have forgotten about too).