os8.6 is still regarded as a solid os: you can't go higher in the [8's] from where you are without paying for it.
from your POV even os9 is unachievable.
osX will be a completely new os, due out in march, i believe.
currently, with all this 9.1 brou-ha-ha going on, if you can get 9.0.4 from a friend for free, accept and be grateful.
9.0.4 is a rock solid os and many are sticking with it for now [and even reverting]:
if you're a newbie, let others find the bugs in 9.1, sit back and do your homework.
don't be so quick to rush in.