Because I've done it a million times and wanted to see what the "random number generator" is capable of? Because I have config backups/know how to unbrick?
You should try it, you might be surprised how thorough it is. It certainly checked more things pre/during/post-upgrade than I did to make sure everything goes smoothly. And definitely more than xattt, apparently ;)
I understand that it works most of the time. I just want to be clear about what the stakes are.
"Because I have config backups/know how to unbrick?" This is the important part for me. I'm not going to gamble with more than I can afford to lose.