THIS WORKED: For anyone coming to this thread via Google, I have a 2011 Macbook Air that was ridiculously slow after an accidental complete battery rundown, showing sub 2000 geek bench scores (instead of about 6000 where it should be). An SMC reset fixed this, I'm at 5900 now and the computer feels three times as fast.
Have you ( or other people ) submitted this into apple to get reproduced and hopefully fixed?
If this is really working as described above ... kind of ugly for other people to have to stumble upon it as they search.