Of the one time I played a demo of it, I found the characters kind of one-dimensional, but very good at what they did. I imagine a regular full game of it might be a bit more detailed in character.
A few extra thoughts:
It's definitely fun, and very easy to pick up on. It also can handle most any pulpy genre there is, but if I recall correctly, very gritty it doesn't do well. It's creator, Shane Hensley, said that he designed it as a game that he in his friends could play a good session, with combat, interaction, and fast-paced fun in a couple of hours a night, because as the gaming population ages, there's a demand for games that don't take a lot of time to resolve things. It does accomplish that goal, from that I've seen, and I've been told you can run some MASSIVE combat simulations with it. It is related to Deadlands kind of like how the D&D minis game is related to D&D.