As usual be sure to do a wipe cache partition in recovery mode. With the amount of time that it took to update the apps after the first boot and how long it took to wipe cache partition I will say that is not optional this time that you should do it.
Hard to say is it real improve perfomance. Got it something like a week ago on nexus 5. So far only I noticed that some applications have become discharged my battery faster than before this update...