Last year and if by clean do you mean were there any problems, no there weren't. It was done online as an update.
All this tells me is that I was a fool to install it in the first place! If this is the standard of acceptable service from Apple they should be ashamed of themselves as Mavericks is hardly a product of merchantable quality.
If it shouldn't be installed as an update it shouldn't be offered as one.
I am not in a position to do as you suggest and don't view it as particularly helpful nor value for money.