Originally Posted by fastair

It is tougher because you now have the CO flyer in the pool who flies on UA sometimes. Before, they were not in the pool, but just got to board with *G or *S, but now, they are competing for your upgrade. I would assume that on CO, with UA's flyers now competing, it is a bit tougher than before as well. But of course if you are a CO double elite diamond platinum president, and you are ticketed on a UA flight for a change, the % of UDU on UA for you just went up from zero, likewise a GS flying on CO chances have increased.