I'm specifically interested in looking for "gotcha" instances in upgrading Kubuntu 14.04.1 to 16.04, to help me decide whether to upgrade or ride 14.04 another two years. I know there's a newer version of KDE involved, and there are significant changes to the underlying Ubuntu (one I just encountered in a [closed as too broad] question was the change from
systemd). The basic problem is, I've already deleted one question of this nature, on the brink of being closed as too broad, and I don't know enough about 16.04 to ask the individual, very specific questions that comments on that question seemed to suggest are the only "interesting" kind or ones that fit this format.
In other words, I don't know enough to learn more here, and I don't have hundreds of hours of free time to become familiar with 16.04 (install the beta in a separate partition, and play with it a lot, while rebooting to 14.04 when I need to get anything actually done). How can I get the information to make an upgrade decision?