I really REALLY wanted to like this show as Ahsoka has been my favorite character in the Star Wars franchise for the better part of a decade. That said, there are some major issues here.
The good: the actors for Ahsoka, Ezra, and Thrawn knock it out of the park with their portryals of these characters. Casting and acting is absolutely top notch, with Rosario Dawson in particular shining and embodying Ahsoka's movements and posture from Clone Wars & Rebels to a T.
The bad: this really cannot be considered to be a stand alone show, and you will not get large portions of the story if you haven't watched at least season 4 of Rebels. Realistically, Ahsoka is the live action season 5 of Rebels, and while the people who are really invested in the franchise and its other TV shows may enjoy the continuity it leaves those who have not watched these other series out of the loop.
The ugly: Sabine - while I think that the actress who plays Sabine did the best she could with the material she was given, I am SO disappointed with this character arc, especially considering how closely the rest of the show aligns with Rebels character development. For whatever reason, recent live action Star Wars seems to follow a formulaic pattern where at least one of the hero's of previous stories is completely ruined, broken, and frankly just a completely different character from the last time that they were seen on screen, so they can go on an awkward version of the heroes journey to reclaim their former selves. You can see this in Obi-Wan & the Last Jedi with remarkable clarity, and unfortunately, Sabine takes the full brunt of this narative choice in Ahsoka. Going from a top tier genius level inventor and scientist, sharpshooter, fighter, and general hotshot Mandalorian, the Sabine we see in Ahsoka is the antithesis of everything that she was previously. She is arrogant, makes dumb choices, and is even a bad shot because of... plot devices? To make matters worse, this doppleganger version of Sabine is nearly elevated to the main character of the series for a substantial portion of the show, again for the twisted version of the heroes journey that Disney seems to need us to take with Star Wars these days.
Overall, I don't think that this is a terrible show, and there are a lot of good parts to it, that said, I had very high hopes for this series, and it did not deliver.