Just got my N6 yesterday and as a crack flasher i have already flashed a few things. Wondering what rom out there has the most crap to play with in it 
My battery life has been excellent with LS and Franco kernel. I get at least 6 hours SOT. The other night I flashed a nightly for it and did a TWRP backup of my current ROM and here was my battery life for it.Just a little status update. I did install LS as the right when i opened the box. As i have been a fan of their work in the past. I went back to stock for a day just to verify stuff worked and then jumped right back to LS.
So far so good.
I loved the battery circle mod, the network stats in status bar, quick pull downs, the dark settings, and i am sure there are more but i don't have my phone in front of me.
The only thing i have noticed was worse battery life, but I haven't given it a fair shake yet, as when it drained i was on the road, or gaming non stop.
I will add more features to this list when i get my phone in hand again. Anyone else feel free to add your favorite features. I did try the circle mod but that just isn't my style.