I have a 500GB TimeCapsule, but I use Mac OS X 10.5 Leopard so I am able to use TimeMachine with it. Yes it took all night to do the initial back-up, so it is pretty slow, but now it only needs to do incrementals every hour, whilst it is switch on at home. It does this silently in the background, so I don't have to do huge back up regimes every week or whatever.
I luckily haven't had to rely on it because of a serious failure, but I was very glad of it when I moved up to the MacBook Pro from the PowerBook G4. When I clean installed the OS on the MacBook, it noted that I had a TimeCapsule and did I want to restore all user accounts and applications to the new machine. I did this and was surprised to see that everything was in exactly the same place as the old machine, right down to icon positioning on the desktop. Now THAT is how backup and restore should work!