Most of the work we've done these past few months was more user-experience than technical, and there's a ton more that we're going to improve as we move forward.
Here's why we're special: Our desktop apps are killer. You can drag and drop a big batch of files in, and we take care of the rest. If someone sends you a thousand files, we make sure those are auto-downloaded, and display them in a way that's easy to browse. Since you're on HN and used to things like Dropbox, you might consider this trivial or solved, but our fleshed out desktop experience is highly visual and is something many consumers find very, very appealing.
Our webapp has a 3-step interface for sending files to any email which was a direct result of hundreds of hours of user-testing. If you've never done user-testing, trust us when we tell you that it's usually a humbling affair. The last time we were on HN, our product was terrible compared to what it is now. It's only going to improve from here on out.
The mobile apps that we're planning will change things. To date, nobody has a way to take a video on your phone, send it to a select group of people and have it downloaded on all the devices they have connected.
Our backend infrastructure is a lot more generic than most other file-sharing services, which enable us to cook up slicker features faster than anybody else.
People also seem to like our customer support.
This was long, hope this answered some of your questions. FYI, we're still iterating on everything, everyday based on user feedback.