Unless you are just being a fanboy, would you care to explain in a little more detail?
Bayonetta in my opinion has got a more complex and varied combat mechanic, it is also more 'flashy', for a while at least it keeps you well engaged when you throw out a new special its great. GoW on the other hand is more arcadey where you hit the same button(s) for combo's however the moves are far more grand, but then at the same time for most of the game you are doing a lot more in the first place. I can't really see how the bayonetta combat would work on the back of collosas for example
It's essentially doing jumping mixed attacks on a very narrow focus vs grand attacks where you hit things on a bigger scale while you are doing other things.
Gameplay i couldn't disagree with you more, the difference for me was i played Bayonetta for a couple of hours and lost interest.
Anyone who dropped Cronos or even Zeus and didn't have a huge smile on their face is not alive, in GoW the middle fights were ok but the boss fights are where it shines
Technically GoW is far superior in every way

landscapes are bigger (the scale isn't even close to gow), graphics are better (art style of bayonetta may be new and pretty but graphically it is not really all that amazing), more complex environments, game runs smoother (although in fairness i ran Bayonetta from the disc), more varies set pieces (boss fights), larger diversity of levels.... i could go on but you get the point
The story in both is rubbish really

, Soundtrack in bayonetta is better though i thought.
In reality you need to play both, while in the same genre they are very different games in both presentation and gameplay. if you had to choose one i would go for GoW every time for sheer fun factor and a more satisfying playthrough
To the op if you still cant decide if its worth the effort, just balance how much you cba against the difference in scores

Source: Metacritic
Darksiders 82/100
Bayonetta 87/100
GoW 92/100
If you wanted to be naughty you could rent GoW 3 from lovefilm or something and then buy the ps3 and return it within the week