Android 5.0 Lollipop Reported Laggy, Fix Incoming
With a whole thread at the AOSP issue tracker, dedicated to the excess amount of lag that accumulates over time while perusing the newest Android 5.0 Lollipop, the problem might finally be going away soon.
If you thought you were imagining things when after 40 hours or so of perusing Lollipop it starts to visibly lag and hang apps at times, you'd be pleased to know that you are not alone in this. It turns out that between all of the under-the-hood improvement, like swapping the kernel and establishing 64-bit reign with Lollipop, Google might have left a small memory leak, which leads to lag and errors over time.
The issue can be fixed with a simple reboot, but that's not the way we usually expect to handle our phones, more so if after 40 hours lag and burn could happen all over again. The problem has been reported, however, and even changed its status to "resolved," so probably Google will be fixing this quickly with the Android 5.0 version updates that are to follow.