Because I also have the same model in 20 inches, there are some differences that personally bothered me. The 20-inch ones have the option to stay closed, while the 14-inch ones do not have this option.
Also, in their center, they have a color from all available colors (rainbow, that is), which is not bothersome if you have chosen open colors, but as I said, it is unsettling when you choose, for example, red and in the middle of the fan you see it turning yellow, green, purple, blue, green, while the rest is red, blue, green. I have them in front of me, so if someone doesn't intend to put them in front, I believe they won't have an issue. When I can, I will change them to put 20-inch ones in front for better uniformity.