In my software, I display popup on hover. I display them immediately because it helps customers to discover, and it looks great with fake data. After 3 month, I add delay, because real users are annoyed with popups on hover.

I wonder how much different the products are to different people. If you subscribe to Facebook/Gmail/a lot of webapps, the UI has nothing to do with the old timers’s UIs. I think they try to keep the UI for a given generation of users.