This reminds me of Cowboy Bebop, but it is not Cowboy Bebop. Spoiler alert, it has a happy(?) ending, Bebop does not. Can Watanabe pull off a happy ending? I think he can, but judge for yourself.
The action is great and the animation is solid especially when considering the character Axel's scenes. With the exception of Axel, character development is a little slow, but picks up in the second half of the series. I came to care more for the main characters by the end of the show than I did at the start.
Is it as good as Bebop? No, nothing could be. But it is a great series nonetheless. Watanabe once again shows you don't need to have hundreds of episodes to tell a compelling story. A dozen or so will do if you make good use of your time.