Comments based on an Emac with 1gb ram, OS X 4.11. User Brilliant with OS 6 to 9 but totally out of it with OSX/Unix.
After numerous crashes and losses of data (caused every time by installing the latest Apple security update), I bought an external USB hard drive, and after some VT research decided on Superduper as my backup system. I should have done things the other way round - on reading through SD's excellent manual, I found I should have bought a firewire drive as a USB one wouldn't provide me with a bootable copy of my HD. Anyway, I persevered and suffered a 22 hour wait whilst my files transferred over. Whilst this was happening, I inadvertently interrupted the transfer, and ended up in a complete mess with corrupted files all over the place. David, the developer was patience personified, and responded with in depth help and support within half an hour of my panic email.
I have now purchased a firewire drive, and the same process took 1.5 hours, was completely me proof, and I now have a bootable hard drive that backs itself up each evening at 2130. Absolute simplicity. I can't recommend this software or the developer too highly.