Barao vs Sterling is going to be a close fight but I think Sterling takes it. Barao just isn't the same guy he once was, 30 years old, 12 years in the game and this will be his 40th fight. The damage he took in the fights with Dillashaw and Stephens was career changing, the weight cuts were career changing. Barao is by no means shot but he is diminished, his prime is behind him.
Barao has faded in every recent fight, almost always has a strong 1st round and then slows done in the 2nd and 3rd. Look at his fight with Stephens, completely gassed in the 3rd. Even in the Nover fight, his movement looks considerably more laboured in the 3rd. Sterling will have a big edge in cardio, I don't trust Barao to keep up with Sterling in the 2nd and the 3rd round. Cutting the extra 5 pounds isn't going to help Barao's conditioning either.
Sterling doesn't even need to take down Barao, he can outstrike him. I think the striking will be close but Sterling is awkward and hard to look good against, I just trust him more in the 2nd and 3rd rounds because of his conditioning. Everyone says Sterling has no volume but he has very active in his last fight, obviously something he has improved on. As long as Sterling shows up I think he takes it, Barao has had his time and he's not at his best anymore, Sterling is on his way up, go with the momentum.