I am not sure you can really compare the two.. can you? I mean they all do different things really.
Sure, they all effect battery, but why would you not use more than one?
I would drop the autokiller that you use, with 2.2 you no longer need that, as it is built into the Os already.
I can't say enough good things about juice defender though, I even paid for the full version!
I must say though, to have JD work well, you need to read up on how to set your apps correctly and whatnot, otherwise you will just be frustrated wondering why your phone doesn't have data.