Okay. Here I go one more time:

I'm not picking a table and then saying "I'll buyin as a short stack because it's safer." I'm picking a buyin amount and using it at a higher level than it would be a max buyin for. I do this for the reason Cocco Bill mentioned, as well as the fact that on "normal" hands, my winnings are determined more by the size of the blinds than the size of my buyin. If I'm going to make $20-$25 no matter what when I get my killer hand, why not make more on the mediocre hands inbetween?