I didn't think it was Midas Whale's best performance either, but I thought Amber did even worse.
I agree about the background singers, they are really noticeable sometimes and it can take away significantly from the performance.
I'm about halfway through tonight's episode. I think Usher's team is my least favorite. Really, there's not anyone I'm excited about going into the live rounds. I don't feel a connection to anyone. I guess I'll root for Garrett since he's the underdog and he seems like a nice guy.