Most of these shows "underperformed" and lack enough episodes to ever be syndicated, so they're going to sink without a trace. Falling Skies was on for five years and they did 52 episodes, so I'd call that a modest hit, especially for basic cable. Extant was a huge mess and lost half its audience in the second season, plus they fired the showrunner and changed the cast, so it's fair to say there was some turmoil on that show. I worked a little bit on the pilot of The United States of Tara, and I think that was a very interesting show. I'd call that a critical success, but not a popular or financial success.