As I thought; thanks for confirming that I can delete those files with impunity.
I've always been pretty neurotic about /Users/artie/Library/Preferences, keeping track of new plists and deleting old ones when they're no longer needed. (I talk to people who've got an incredible number of plists, many for apps and processes no longer in use, and others with no known purpose [at the moment].)
BTW, that folder is normally hidden isn't it? That's Apple's way of saying "no touchie!"
Apple tried "no touchie", and judging by the relative ease with which it's now overcome it obviously didn't get a very warm response. (I don't know about you or others, but I visit my home folder many times every day and wouldn't care to have to "Go" to it.)