I used to have Carbonite for my wife's iMac. It was a little slow to backup but worked on till we actually needed to recover all data after a HD failure. Since then I couldn't dislike Carbonite more than I do. The first ten minutes of the recovery process the disclose was fast. Then it continuously slowed down. Of course customer support blamed it on our connection which was complete BS. I then started downloading the files were needed most through their web UI which was not bottlenecked on their end. However, there seemed to be done restriction on their end on how many files you can download at once. The limit seemed to be around 100 files. If you download too many you will see a spinner minutes and then download a empty tgz. It was incredibly painful and tedious. We have up on most files. The entire idea of unlimited space is obviously not viable and something gotta give. Apparently in Carbonite's case it's the download bandwidth. Should have seen this coming.

I can't dissuade against Carbonite strong enough.

We now have a NAS and back up truely important data to S3 and iCloud.

Well, shit. I just switch da wife to Crashplan, touting its several advantages over Carbonite (which she was happy with). Now I'll have to eat crow and switch her back. :(