@Ice-Ice Yeah, that's unfortunately expected. In this update we moved the plugdata folder from an OS specific path to the user documents folder. This makes it easier to find, or to explain where it is. I also wanted to have a clean start, because we saw some issues with people using plugdata since the early days, where their settings file had gone through a load of updates, and contained a lot of old trash.
The new add menu only allows drag and drop, no clicking. This has caused confusing for more people, so next version you will also be able to click them.
And nice to hear! I also came from Max, but I wanted to work in a DAW of my own choice 
