Backup speed is not that critical
When you are backing up, then sure... a quick backup is always appreciated. Then again, just backing up, in of itself, is a sound practice, fast or slow. Just do it.
As long as your working PC is ONLY container for your images, everything is at risk. You need a safe, reliable, and consistent method that WORKS FOR YOU. With the newer, larger files being created, daily, you need to process your captures quickly and with the understanding that they could be lost to any number of catastrophic events, if you leave them in the PC. Copy them off, plain and simple. Then tuck those copied files somewhere you know is safe. I mean better than your old family album, because when digital media ages... it all goes.
You also nee to catalog what you store, because as I recall, looking at one recorded DVD next to another, I know this may sound non-PC, but I cannot tell them apart. :eek:
So, you have to include some kind of listing to rapidly make use of your backups, one day.
I hope I am preaching to the choir on this, because it is a necessary overhead item to any photographer's work, professional or... otherwise.
Good luck with whatever method you make use of. Obviously, some are more reliable than others. Just do it.