The story is good. Really good. Definite Clone Wars vibes. The young actress playing Princess Leia is perfectly sassy and brings a lot of energy to every scene she's in. In later scenes she absolutely kills it in dangerous situations. Ewan McGregor is remarkable as an Obi Wan struggling with his regrets. Joel Edgerton brings perfect protective grumpiness to Owen Lars.
Now the not so great. Grand Inquisitor still looks almost exactly like Pinhead from Hellraiser, and has all the menace and emotional range of the plastic Halloween costumes that were popular about the same time. Seriously, seriously missed opportunity when I'm seeing the Rebels cartoon version as much more intimidating than live action.
Moses Ingram doesn't sell her character in the beginning, but she gets much better and by the end her performance is stunning. The character is written to have a menace, a simmering rage that just... Isn't there at first, but as the character gets more complicated the actress really gets into it and it's wonderful.
I just have the general impression that the showrunners don't get inquisitors, though. Bail and Breha are good, and the dynamic is very much like what's in the Leia book. Obi Wan, well, you have Ewan McGregor, and I think he's been watching the Clone Wars, so that's clearly awesome. But the Inquisitors are clearly not an enemy the people in charge are excited about, and it shows.
As for Vader, he's amazing. There's a lot of grumpiness over the first big fight we see, but remember this is a journey for Obi Wan and the middle is supposed to suck for him. Hang in there. The payoff at the end is worth it.