I think from a backup perspective, cloud backups are very convenient, but for restoring any large amount of data, that could be very time consuming, depending on your connection. Most ISP downloads are much faster than uploads, so that could work.
For me, the slow upload speeds are the deal-breaker for cloud backups - even if cloud storage weren't horrendously expensive. 24 hours a day isn't enough time to do the backups.
Obviously, hard drive storage is cheap and local and if you care about your data, you have multiple drives (or a RAID solution) to have multiple/protected copies.
I use multiple RAID drives - since some RAID failures destroy all of the data in an instant. (A simple, single drive failure is recoverable. A controller failure that destroys the array is not.)
The optical solution is good for things that don't change, like completed Final Cut projects or music or movies (there's that DMCA concern being raised again). I've looked into putting larger-than-4Gb projects on BD, but at this time, it's not a solution that I'm using, mostly a financial decision (saving my money for a RAID solution).
You mean "larger than 8.5 GB, right"