Re: I might have a look at one of these...
I've had very few problems with Lollipop on my Nexus 4. About the only annoying things are
Occasionally it will use an unfeasible amount of battery for no reason. A reboot fixes this but shows that the battery level is actually a lot lower than the reported prior to reboot.
Sometimes Now launcher does not launch and Im stuck with a blank screen - again, a reboot (or sometimes launching camera or phone from the lock screen) sorts this out