When I open a directory as a project, it's normally quite quick and appears instantaneous.
When the directory has many files (say, 60,000) the process can take a few seconds. More files takes even longer.
Commendably, the UI of the program doesn't hang during this loading. However, there is no indication that any loading is taking place: no progress bar anywhere (not that I know where one would go) and the status bar only updates when the loading has finished. During this time, the Project menu's Open File in Project and Find in Project menu items are grayed out, giving a first impression that the loading has failed. I guess it would be nice to get some sort of idea that loading is taking place.