I have three Windows 7 computers so I decided to try out W8 on one before the Jan 31st deadline for the $40 upgrade.
I bought a new SSD and did a clean install on it. This allowed me to dual boot to my legacy Windows 7 drive and to the new Windows 8. I recommend this for anyone who wants a clean install but is concerned about access to their "old" system.
After a few weeks, I still find W8 cumbersome to navigate, a pain in the arse to shutdown, and too much advertising drivel that had to be removed.
I decided I'm going to save $80 and not upgrade the other systems. I'm using the money towards putting new SSD's in the other machines.