First off, what exactly is Ubuntu One? Well basically it's a file sharing and synchronisation service from Canonical. The basic package is free and provides a reasonable 2GB of storage. Canonical claims it's your personal cloud.
So my first impressions? It sucks. Canonical produces client software for both Ubuntu 9.04 and Ubuntu 9.10. However support for 9.04 seems pretty feeble. There's no Tomboy notes synchronisation for 9.04 as there is in 9.10. Which makes that feature useless if your not the type to dive in and upgrade all your PCs all at once.
Even worse however is the file synchronisation feature. It just doesn't seem to work. This being the basic concept of the whole package anybody would have thought Canonical would have gone out of their way to make this work. But it seems not.
So far I've been able to get files and indeed whole folders to upload my Ubuntu One storage space. But they don't ever seem to download to the other PC. It doesn't matter which PC does the uploading. The other PC just doesn't "synchronise" with my on-line Ubuntu One storage space.
Now the client software isn't the only way to interact with Ubuntu One. There is a web interface. But then again there are loads of places on-line for me to upload my stuff to that I can later download from using a web browser. The point and attraction of Ubuntu One is the desktop integration. Which just doesn't seem to be working properly.
Frankly I get a better service using the 50MB of free web space my ISP provides me with. It's simpler to set up as well. All I need to do is FTP into my web space from Places > Connect To Server. No software to install. No PPA to setup. Just a user name, password and FTP address. It's also 100% compatible with both versions of Ubuntu I'm using at the moment.
Perhaps Ubuntu One will work better when I'm running Ubuntu 9.10 on both PCs.