These few days, i have tried Color OS and CM11S.
Was really curious why so many people love CM11S before i got OPO, tried it and dislike the experience. Personally.
Google Service is draining battery like mad. (Not rooted, lazy) Which also tells me CM is still buggy all these years. Yes it's a continuous development, but we users deserved something more stable.
I tried ColorOS, although no GAPPS, but it's a simple flash of GAPPS.zip
It seems more stable and battery life last almost twice as good as CM11S.
I think i might go over to ColorOS and use it before CM on OPO becomes really really really stable. Quite disappointing.
Speedwise, CM11S is faster than ColorOS, but stable-ness and features and feels. I think ColorOS feels a little more unique. CM11S feels like just any other Android ROM to me.
Just sharing.