I've played my last game with starting position #518.
Chess960 is harder for opponents because they don't have their pet opening systems to hide behind. During my last game of #518, it came clear why chess960 is more than worse for them, it's also better for me.
For as long as Alekhine's Defense has been putting me in this position, I've figured it was OK — it's an interesting sacrificial position; Black has a lead in development and a better center. But as I sat at the board, I had trouble bringing my eyes into focus, and when they did come together, I saw this strange position and thought: "What the heck am I doing here? Where did all this come from?". I compared the long string of book moves (where I disobeyed my genuine chess instinct in favor of a less successful but more popular move!) to the interesting #454 gambit, where my brain was engaged immediately — in theoretically-familiar #518 games, I'm sleepwalking; in chess960 games, I'm more present in the chess moment.
I determined that I'm through with position #518, in which opponents are booked (even if their books are as short as 1. Nf3 2. g3 3. Bg2 or 1. d4 2. Nf3 3. Bf4, they are in somewhat-foolproof territory). The other 959 positions push opponents away from their comfort, which they don't like, but they push me to be present at the board, which I do like. So those are the positions I'll play from now on.