The ability to send files, images or video from one person in my office (or anywhere) to another without having them physically there is great! I have used it for sending documents back-and-forth with clients who are out of town and can't be at their desks when we need something signed/approved etc.
It's been very helpful so far - no complaints here :) We use this primarily as an internal tool but also occasionally do client work via remote meetings using GoToMeeting. This has made those calls much more efficient by allowing us all to participate remotely instead of everyone being present together which would cost way too many dollars per meeting.