I also have 14.04 LTS and received the update last night. But anyway it acts like a new computer...much faster. Also I think I had a flash player problem that it fixed because my streaming radio station isn't freezing up anymore.
There would have been a new Firefox (44), which proported to have better media playback and may account for faster general performance; and there may have been a new Linux kernel, which might explain a faster boot time.