I'm generally not too concerned about the speed of the process because it's something that's done once, and then never again.
It's generally a "set this up and walk away" process for me.
That's how I'm looking at it. Start the process and go have dinner. Or better yet, go to bed!
Righ now, for example, I'm writing zeros to my new set of 300Gb hard drives. Now THAT takes a while. Definitely time for dinner.