Adele had a bad night. She was consistently flat and had trouble hitting notes at all. I didn't like the song much and thought it was very technically difficult. Not a good choice.
I was amazed that Gaga wasn't totally out of breath at the end of her medley. I liked the set.
This is what happens when performers like Adele are placed on this Neo-queen of soul pedestal. Under pressure, it's either great or a wet fart. Gaga on the other hand is a true performer and I can't say I've ever seen her fail to deliver. All Adele has to do is sing her best. Gaga sings her best and brings much more to the table performance wise. It's no wonder they trust her with the better material. I'm not knocking Adele, she's a great singer, just not quite as multi faceted as Gaga. Vocal timbre is debatable.