CM11 vs. CM12/12.1...
Why you don't use CM 12.1 ?
Well, i am not him but..., i own several phones, all Samsung, with JB stock, CM11, KK stock, and LP stock..., i haven't tried yet no CM12 or CM12.1 (only for several minutes, for fun of flashing) but my experience with stock LP is much below the other, although this one it is several times better in terms of hardware than two of the other phones. Is not reliable and freezes with no reason, even when is not used...
Anyway, overall experience is far worst even than JB, and that on a good hardware!
So besides LP is very hard on accepting Xposed (wich is very important, at least for the name "geek"), KK is by far the most reliable Android to date.
I've tested the above configurations of OSes for several weeks just for experience and testing, and of course i plan to downgrade to KK, it is a Galaxy S4 i9505 and it is known to accept the downgrade, i've tested myself the downgrade just after i've bought it.
So, this is an answer for this question, wich i've also been asked few pages back on this thread