Well im happy to report that my Smultron ST15i is running 20141224 build nicely. Very stable. Havent had any reboots. Starts reasonably fast (could always be faster) but then again i use xposed bootmanager to kill useless stuff trying to run on boot. No major lag observed. About 90MB free in internal /Data (system apps ODEX-ed and buch of useless CM stuff removed + bigger apps moved to SD card). Not using any mount2sd or equivalent.