I have used it for like 5 years now, I have had some problems during that period, one time, it disappeared a lot of my files, hundreds, I couldn't find them anywhere. After contacting support, it resulted that an unknown issue caused my files to come orphan. They were on any folder nor the deleted items. The recovered my files, but I have to reorder them in the file structure, it was a pain.
Also support team is not good, I have contacted several times for different issues and regulary they respond as machines, without paying attention of what you are asking, almost like predefined answers to words in your questions... You have to insist and insist until they scale your issue to a different level, does people do read. They don't have telephone support on demand, but sometimes, if there is an issue, they suggest to make you a phone call and give you remote support (live).
The ability to share big files with people outside the organization, it also helps sharing folders with people that don't have SugarSync and of course, the main, it allows syncing files in almost real time between all my devices. I actively use 4 devices (work PC, home PC, laptop, mobile).