Well I started reading about this stuff and I'll admit I've never felt comfortable enough to start swapping kernels. So instead I went back to an old friend and tried the latest cyanogen nightly. Normally I'm not even that daring, before when I was using them I went with the milestones.
So far on nightly 4-10 I have experienced one instance of picking up the tablet and it being completely off, I had to power it on. No idea what happened there but leading up to that I noticed the memory creeping up to critical like it always did stock. I also had one instance of nova launcher failing to appear, just a black screen for a while. Now that happened a couple times when it was stock too so I'm thinking nova doesn't get along with the N9 so much. Nova works great on my Z3c and N7'13 though. I've also had some weird video playback problems in netflix, video so laggy the sound wasn't playing the same place as the video was showing, I've never seen that before.
What is improved under CM12 is the speed, it seems to fly and not suffer weird pauses here and there. But with only 6 hours of uptime on the tablet so far lets see how it does in a couple days because stock after a reboot was fine too.
Honestly at this point I might pay someone for a rom that was trouble free and an easy flash like cm or stock is.