I'm currently testing several backup/sync services: Dropbox, SpiderOak and Ubuntu One. Of them, Dropbox is the winner hands down; SpiderOak is nice too, but a bit more intrusive and unpredictable (sometimes is slow in syncing some files, or doesn't sync them at all). Ubuntu One has promise, but I've used it much less than the other two.

I'm thinking about buying a "20 pack" and using Ubuntu One as my only synchronization software. It's the cheapest of them all (3$/month vs 10$ in Dropbox and SpiderOak), and 20GB of space is enough for me. My intention is to sync most of my $HOME folder. All the computers I'll connect will have Ubuntu installed, so not being multiplatform doesn't really matter to me.

If its performance is as good as Dropbox's, I'm sold. But I'd like to gauge some experiences here first. Is anyone using it seriously? I.e., to sync a lot of files that change often (like the aforementioned $HOME folder, program sources, or something alike). What have been your experiences?

Thanks in advance.