I dropped Flash and Aquaman because while I really like the associated creators, the pieces just didn't come close enough together for me. I particularly find Williamson, Abnett, and Walker more inspired elsewhere.
Action Comics is a pretty average book that looks worse when you consider how strong the other titles in the franchise are holding. I really find the art bland, too; the only book aside from Flash and Titans that I don't dig on that front.
Strangely, I'm the opposite with JL as I have really enjoyed the first few issues. I didn't get the Rebirth special but I will get the latest issue some time today.