Faster upload, more security etc.?
I strongly suspect the bottleneck on upload would be the users connection rather than the companies hosting, although I guess they could do traffic shaping when load is high to give bandwidth priority to paid up users.
Security wise, its already pretty secure on the computing side (see the FAQ), and it appears they've gone that extra step on the physical security of their servers...
The servers are hosted in a former gold bullion vault. You can imagine how seriously the Bank of England guards its gold. Now, we can offer you exactly the same protection for your files because we run the building.
Don't plan to upgrade myself, seems fine as it is.