In my opinion, Andy has played a similar game to Dan in season 10. He laid low and floated through the first half of the summer, was friends with everyone, has been unwaveringly loyal to one person (Spencer), won challenges when he needed to, and has very impressive powers of persuasion.
I had a dream two weeks ago that Andy and Spencer were in the final two, and now that we're almost there, I think it's going to come true. The only way GM gets to F2 is if she wins the final HOH competition -- I don't think either of the boys would take her -- and the odds are against her now.
If it does end up being Andy and Spencer in the Final 2, I don't see any situation in which Andy loses to Spencer.