13500-13800 score (5 tests) on CM10.1 B6 with XM-Kernel #134 by xmister. I'm underclocking at 1200mHz and undervolting at -150mV, i'm using touchdemand as governor and ROW as I/O scheduler.
CPU max temp during stability test was 45 degrees celsius.
Ten days ago on the left, just now on the right. Nothing changed in between. I wouldn't read too much in to it. I've noticed the 2D graphics scores fluctuating on some of the tests people have posted. I'm guessing it has to do with the graphics drivers which we know are hosed because of all the graphics issues. Once they are updated we should see more consistent AnTuTu scores.
I can only share what I know from watching Asus and Nvidia try to opimize the Prime. Battery life and peformance, especially the behavior of the multiple cores, are linked. So to improve battery life they played around with the stepping of the cores and in one update even locked them below the 1.3Ghz max clock speed. By the third update the *****ing stopped so I'd guess they found the right balance. But a 25Wh battery in a tablet gives you a lot more to play with than a 1800Mah battery in a phone. So time will tell.
The graphics drivers are a side issue and were also experienced by the Prime. They were easier to resolve.