According to saps, jt's non-voodoo and geeknik's stupidfast are pretty much the same kernel's when it comes to using them on the phone and you wouldn't notice a difference. That said, I've been with Geeknik's (I've ran every one he has released, current is in sig) as has saps (who has tested them). I know nitsuj's been running with jt's as far as I know (correct if I'm wrong). So I would say you couldn't go wrong either way, they have both had very positive reception.
One thing I would recommend when getting rid of voodoo. Make sure you have adrynalyne's uninstaller on your SD card beforehand, like nitsuj said. I didn't when I went to uninstall and mine got stuck right after the Samsung logo. I couldn't mount the SD and couldn't push the file through adb either. I ended up having to swap my SD out with a family member's Android phone and load it on there when it was in their phone. So I would do that as a backup, just in case

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