I like that if anyone is doing something wrong with my document, they will be notified of it so quickly! Sometimes my files don't show up after uploading them to secure drop (my computer does), but this usually gets fixed within minutes/hours.
It's very easy for me as an employee working remotely or someone who would otherwise not have access to upload attachments directly into their office computers. The best thing about all these problems are how much easier everything has become in general since using Secure Drop because there aren't any more security concerns from our end anymore.