Superman is my favourite character but personally I can't stand what Bendis has done with complete control over both Superman comic books. Granted Bendis is one of my least favourite comic writers of all time so him writing Superman is a personal nightmare for me but there's plenty to criticise about his Superman run as well as praise.
Superman follows the Rogol Zaar plot line from MOS and eventually covers what happened during Jon's trip with his grandfather Jor-El. Rogol Zaar is still the same bland, one dimensional brute that Bendis has convinced himself is more important than he actually is to the story. Making Rogol the cause of Krypton's destruction is an embarrassment to the richness of Superman's mythos. Also Jon Kent eventually turns back up only he's been aged up to 17 and has a scar after spending years trapped on Earth 3 in the past. So Bendis robbed Jon of so many more stories that could be told at his younger age just to rush him to a point where he wants to tell his story which is unfair to say the least. And Jor-El was apparently a part of a secret galactic Illuminati called The Circle which once employed Rogol as its enforcer. Very generic, drawn out filler that is typical of Bendis whenever he tries to tell an epic cosmic story. It's never been his strong suit as most Marvel fans can confirm.
Action Comics deals more with The Daily Planet and Metropolis side which follows up on the fire subplot of Bendis' MOS. It introduces a new group called The Invisible Mafia, a new villain called Red Cloud, a woman who now owns The Daily Planet and reveals where Lois Lane has been since returning from space. This is the more critically acclaimed of Bendis' Superman series but I really don't see a big difference in quality. If anything, some of my least favourite moments and dialogue has come from Bendis' Action Comics. Expect more drawn out decompressed storytelling with frustrating Bendis speak peppered in throughout.
You'll hear plenty of recommendations on here since many users are fans of Bendis' run so I think it's only fair you also hear some critical opinions too. Obviously the first trades of Bendis' run are out now so there's an opportunity to return to reading Superman comics if you like what you hear. However, if you didn't like the MOS mini, you'll probably find Bendis' run is more of the same in my opinion.