Dumb Question, or rather Moot Point.

Last i checked a big percentage of bikes were stolen from home. So... what $ bike would you leave locked, and where and when. All addative factors.
I'll lock any bike to a rack, just depends on the rack, the neighborhood and the locks i use. I've locked nice bikes to a rack (you can't always bring them with you.) and locked my best and only overnight at the local gun and knife club hospital. You can't fool every theif in the world, but you Can beat every one in your neighborhood.