I got an Abel arm rest so that I wouldn’t mess up the French polish on the top. It’s working great. I bought it to make sure that my arm doesn’t touch the top if I play in t-shirt. It also makes playing a lot more comfortable (which I didn’t really expect but also did no research on because it wasn’t crucial to me). The nicest change to me is that it improves the tone because it allows the top to vibrate more freely. I’m happy that I got it! (Mentioned here)