So I decided to render the picture at Ultra, and it took a couple minutes to start, the prepass took about an hour, and before I went to sleep it was at 1% and was forecasting that it would take 200+ hours.  But when I woke up this morning it was done, and said it had only take 5 hours, so I guess it just starts slow and then speeds up or something.  I think I'll put it back on User Settings and see what happens....