I've upgraded my little gt-i9001 from cm10 JB 4.2 to cm11 KitKat 4.4.3 last month. The result was a big battery drain.
I thougt my battery was faulty...
But some users have reported the same problem.
Hopefully, the XDA team bas released the KitKat 4.4.4 .
I've taken the opportunity to upgrade to the latest version.
Result: No more battery drain.
The gt-i9001 is my very first KitKat android...