The Good - Zombies Everywhere
From the very beginning, Gale Anne Hurd, Robert Kirkman and others have let it be known that The Walking Dead would be a human character-driven drama where zombies played second fiddle to much greater threats. Sure, there have been plenty of high-tension scenes where it was unknown if a member of the group would survive an encounter with a walker, but until season 6, zombies have served more as obstacles in a maze than actual antagonists. All that was turned on its ear in the first three episodes this season, as a massive horde was introduced that threatens to change the group's way of life forever.
Zombies have always been knocking at the door, but this is the first time where simply dispatching or ignoring them isn't an option. The horde is so large that it's directly affecting the decisions the group makes in regards to their safety and the town's well-being. The group must take unsafe actions (such as riding slowly in vehicles as thousands of walkers follow them) in order to deal with them directly. This aspect alone has greatly increased the entertainment value of the show.
The Bad - Not Enough Carol, Daryl and Abraham
For five seasons, fans have fallen in love with Carol, Daryl, and Abraham in a way that means it will indeed be a dark day when any of them are eventually removed from the show (and it should happen at some point). The show could be centered entirely around them and most fans would be entirely OK with that - so where have they gone in season 6?
Carol fooled almost everyone in Alexandria (except Sam) into thinking she was a cookie-baking homemaker until episode 2 " JSS" when the Wolves stormed Alexandria and she revealed her true self as a badass killing machine. It's probably the best episode of the season thus far and one of the top five episodes with Carol in it. Sine then, however, the show has literally reduced her role to that of a babysitter - which makes no sense. Meanwhile, when Daryl and Abraham (two of the show's other bad-ass characters) aren't riding slowly in a vehicle, they're spending their precious little screen time running from unknown assailants or hiding in office buildings.
Now that Daryl, Abraham and Sasha are making their way back to Alexandria, hopefully they'll play a more prominent role and audiences won't have to endure anymore filler time with characters they have very little interest in.
The Annoying - Plodding Exposition Filler
Speaking of things audiences have very little interest in, the vast majority of the first seven episodes this season have been packed with meaningless character exposition. It's common for a story to intersperse exposition between action or intense scenes as a way to allow the audience to catch their breath, but there's been so much of it this season an entire 45-minute episode was dedicated to telling Morgan's life while he was wasn't with Rick.
Morgan's backstory could've been summed up in a couple of flashbacks during one or two five-minute scenes. Instead, audiences are treated to Tabitha the goat and couple of throwaway Wolves, which is a complete waste of time since it was established at the end of episode 2 that Morgan has a connection to them. Also annoying is the time and effort taken to introduce a new character, Eastman (John Carroll Lynch), quickly develop him to the point that audiences appreciate him, then kill him off just as quickly. Why do something that extreme if the producers aren't just marking time until the mid-season finale?