Root Cm7.2 to apocalypse rom?

[ftwcookies]

so i hear apocalypse is one of the best roms in terms of battery life so i want to try that rom

do i need to go back to stock or can i install apocalypse straight from cm 7.2 via cwm?

 

[ayush29k]

so i hear apocalypse is one of the best roms in terms of battery life so i want to try that rom

do i need to go back to stock or can i install apocalypse straight from cm 7.2 via cwm?

Its the best in terms of battery only if you are considering CM roms, stock roms still have a better battery life than this.
If you have a rom that has ext file system then you can flash this over it. All CM roms have ext file system, so yes you can flash it via CWM.
Although it has been known to be a bit difficult to get a stable working rom after flash, so its better to flash stock first but there is no harm trying to just flash it over a previous custom rom, it worked for me. I didn't have to flash a stock first.
But many people reported theme problems, multiple force closes and settings problems when they flashed it without going to stock first.