It is a myth that CM10 is 100% better in every way than CM9. CM10 is definitely better, but...
CM9 generally gets better battery life.
And JB gets the stutters when scrolling. This is MOSTLY worked out, but still comes up. I consider this a non-issue at this point... so it's really just the battery life.
Joker's MIA, so CM9 itself is unlikely to be updated. When CM10 was first coming out, the word coming down was that CM9 would continue to see development. So there is something to be hopeful for if you really don't want JB. In the meantime, check out CanonROM 1.2
... it hasn't been updated in a few weeks, but I've ran it, it's solid... it does include Google Now, and that works, although sometimes it doesn't (it's the ICS hack) but generally it's good. Only I wasn't getting any better battery out of it, so I just came back to JB.
Samsung Galaxy S3 / US Cellular / stock 4.1.1