Chris, I think you have stated the pros and cons quite well. A two sided clipless pedal is easier to use, because you're never on the wrong side of the pedal, while the dual purpose pedal allows you to ride in a variety of footwear and the option of pedaling clipped in or free while riding in your bike shoes.

I'm also considering changing pedals and am having a little trouble deciding which pedals should go on which bike. I have a pair of used dual purpose and a pair of new clipless on hand, patiently awaiting my decision.