I like that you can easily share multiple files at once without having them all open in tabs or windows as well as being able to have access from different platforms (PCs & mobile).
There's no way for me to sort by date modified so it would be nice if there was an option where they could see when each file last changed instead of just seeing what is most recently added. It helps us keep track of things we've shared internally between teams which has been helpful during our transition into using SharePoint more often now than before!