I think whatever automated process they use is both very conservative and faulty. It does things like:
*Booking you for the next day when there are same day flights;
*It never reaccommodates you under rule 120.20 on a different carrier;
*Even on an F award it booked me on a double connection in Y for the reaccommodation, but an agent rebooked a nonstop F that was available.

It almost seems like the computer looks for wide open flights, and won't do anything much to accommodate the customer. I've literally never kept and gone with the reaccommodation suggested by whatever this process is. An agent has always booked better options.

I am also curious what exactly triggers this reaccommodation job to kick in. I mean is it evry misconnect? At what point does UA decide/predict you are a misconnect? How do the nuts and bolts of the process work, etc.