You might want to check out the United UDU tracker
http://www.udustats.com


SFO-BOS looks to be a really tough upgrade. Only 11% for 1P (Premier Exec) and only 20% for 1K reported.

http://www.udustats.com/Home/SearchR...eliteStatus=1P

Overall 1P is batting 67% on United for UDU.