pdlamb: I've thought of that. It's a mental tradeoff - losing whatever style points I may still have vs. the intimidation factor (amplified if I ride my commuter vs my road bike!) vs. the "I'm going to be slower because I'm carrying all this junk).
caloso: I've thought of that, too (but needed the reminder!). I already leave toiletries at work, and can just use the commuter and a larger pannier for the next day.

OP - sorry for the thread-jack. Working training into a commute is a great use of almost free time (just don't wipe yourself out for the work day or whatever you have to do at home). And you'll be able to have conversations like this one: http://comics.com/frazz/2011-05-13/