2013 Nexus 7 LTE (Deb)
After applying the update to 5.1.1. I have noticed quite an improvement in battery life and performance. The boot up time hasn't been helped, but the speed of apps loading and it has become more responsive.
The new Team Win TWRP recovery that has been released for it 188.8.131.52 seems to have some GUI problems, progress bar has stopped working and a couple other cosmetic problems. General functions are solid though.