I own it, and I couldn't put it down. I despise DMC and GoW, as I find them boring, but I LOVED this game! It also allows you to buy alternate costumes after beating the game, adding some replay value.
the story is basically thus( I haven't touched the game in a while, so take it with a grain of salt): Bayonneta is an Umbral Witch, the last of her kind, fighting against the Lumen Sages, who use angels to do battle, while the Umbral Witches made contracts with demons... Man I need to play this game again, I can't remember the rest... INSANE final boss fight though.
Bayonetta is full of sexual energy and she's not afraid to flaunt what she has. She is OOZING 1960-70's sexual empowerment. MovieBob(aka The Game Overthinker) and The Escapist itelf reviewed the games, I'll give ya links!
Here's the Escapist's review: http://www.escapistmagazine.com/articles/view/editorials/reviews/7024-Review-Bayonetta
Here's MovieBob's character analysis of Bayonetta herself: http://gameoverthinker.blogspot.com/2010/02/episode-32-i-heart-bayonetta.html
By all means though, I highly recommend this game! One of the few games I bought brand new, and felt was worth my full $60. It's not TOO short either, my first playthrough on Normal was around 20 hours, and once I tried on hard, after keeping my stats and weapons, I STILL Got slaughtered. On the first level...