As for working out of the box...
...I have just had an experience. Old box threw a wobbler and killed a disk dead, dead, dead. Sad, sad, sad. Doing it while backing up said disk and thereby scrunching the backup set too is just icing on the cake - plenty of backup survived and I could rebuild the machine in a day or so, I figured. New box arrived, destined for Windows-XP-hood. But guess what - XP Pro didn't recognize the NIC on the motherboard. No amount of badgering made it understand that yes, there's a NIC down there and it's perfectly capable of contacting the router for an IP address. Ubuntu did it right the first time. And everything else in the machine too. XP never quite got the hang of the old box either, with several pieces of hardware sporting yellow question marks in the device manager and no relief to be found anywhere. Not that I was missing anything (I'm not into gadgets so I'll survive not having a card reader, teevee card etc.), it was just a bit weird.
Now I know I've taken a few shots at Linux in the past for being not quite good enough, but even I have to admit that Ubuntu's nearly there. A few issues (mainly with off-mainstream software like VMWare Server (which sux - now using Sun VirtualBox instead, great little tool)) notwithstanding, it's doing a marvellous job. Now if just IBM could manage to get out Domino Designer and Admin clients for Linux I'd be happy never to see a Windows box again.
Ubuntu One is pants though. Overpriced and underperforming. Where's the ability to link in backup software, for example? And it's not as if the incentive isn't there, 2 Gb is going to disappear in a flash once backups start rolling in and people will then probably be happy to dump a load of money on the service. Try again. Please. It's a good idea, just do it right next time around.