Cm9. Here's my experience so far. Very snappy, great battery life.
Gallery is finicky, I can go through the images, preview for vids no go nor playing them. (I'd rather use gallery than a 2ndary app.)
Tapatalk f/c more often than normal, especially when images are involved.
YouTube works great cept for HQ is a slide show.
Batt stats doesn't work properly, but data usage on 3g works like a charm, or so it seems.
All games I have tried work flawlessly, angry birds space always f/c on iho for me, but cm9 works great.
Speakerphone does not work. when calling people if they have a image associated with the contact, the image is blown up huge.
Browser works great but sometimes the page will not show but is there as I can click links.
More as I find it. Overall great build especially for beginning stages!
Btw this is my experience which may differ totally with yours, if any bugs are already posted, they are in my list to confirm you are not alone.
Sent from your mom's phone.