There were some really good arcs after the Mortis episodes, including the Citadel and Umbaran arcs, but I agree - wildly uneven. The first couple seasons were great, then you starting getting arcs about nothing but droids that would have found a better audience in something like "Detours."
They had some great character development over the whole series, but many were left so unexplored and didn't receive the treatment they deserved. I'm glad
Ahsoka left on her own accord, and I hope we see her again.
Also, it would be nice if Rex learned lessons from the episode "The Deserter," and doesn't get caught up in all this Order 66 business, unfortunately, I feel like this is a long shot.
These are the two characters I've come to care about most in this series, and if they give them decent endings, I'll be at least somewhat content with the way things ended.