Agreeing with Retro. I really enjoy the idea that Mashima has going, but the execution is awful.
Most of all the conflicts are solved almost immediately, and they never shake up the status quo. Let's take the Dragon slayers' disappearance. Instead of revealing their whereabouts right away Mashima should've kept the reader hanging. Let the guilds be in despair so Erza can shine in a leader-role. Have them fight against Acnologia's physical form and having no idea what's happening. The only thing they know is to defend their home, hoping their allies are alright.
Instead we get a constant switching of scenes while characters provide exposition. And hell, in most manga we at least get some big event where everyone is reaching out to the heroes and their voices reach them. This was laughable.
But at least we're finally getting some dragon slaying.