I use selective sync, and I happened to tick on a large folder which eventually didn't fit on my harddrive.
First of all, the harddrive got full; is there a way to put a limit on dropbox so that it never fills up the last five or ten Gb on a harddrive?
Second: obviously I unticked the folder again. Space is slowly freed up. Very slowly. It will take days in that speed to recover the space that the folder took. WinDirStat reveals that 13% of the harddrive are jpg-files that reside in "<unknown>" and my guess is that these are the files that dropbox once downloaded and now has released.
Upon unselecting a folder in selective sync, my expectation would be that dropbox instantly is using a lot of disk because it is removing the files and freeing up the space. But it doesn's seem to use any disk according to Task Manager.
Looking at diskspace in Explorer, the free space increases at maybe one Gb/hour.