Honestly, I’m still using the service and have no complaints. The photos taken on my phone are automatically uploaded to my account and are easily accessible via my computers. The service is rock solid and integrates easily with the Unity and Unity-2D desktop interfaces.
Oh, and I might have forgotten to mention that with the one million user celebration, the 2GB Ubuntu One Basic service has been upgraded the the even more attractive 5GB Ubuntu One Free. Ahhhh, freedom.
Sources: Ubuntu One celebrates 1 million users – The H Open Source, A big thanks to our 1 million users: have some storage on us! – Ubuntu One Blog