God I used to love that thing. 50+ miles of rural bliss. It's one of the best things about Atlanta. I started riding it from about 1999 and I recall when it stopped a good distance prior to Cedartown. They just kept working on it and adding more, all high quality infrastructure. It is one of the great attractions of Atlanta now. I do think it has become a bit overtrafficked now, I recall having to pick my biking times around all the hikers by about 2006. You can still ride like a maniac on it but you really need to keep off it during family hour.
Silver Comet Trail wiki