I like the character customization, and I do indeed use it. Some might say that it adds very little. A few hair styles and eye/skin/hair color, but big deal. You can change their weight, big deal. I personally like it, for role playing purposes. I can make a character completely emaciated, morbidly obese, and everything in between. That, for me, is great. As far as adding anything to the game, no, it doesn't. A skeletal figure can swing a giant claymore just as easily as a big burly beefcake. But that's not why I like character customization. I like it for the fact that all of my characters have backstories. All of my characters start off as slaves in the gladiator arena of Exanima. Each character has a very specific body type, for a variety of reasons. So, body customization is greatly appreciated by me, as it visually aids in me transitioning my characters from the arena into games like Skyrim and Wolcen. So, while the general player might not have much appreciation for it, I do.
However, I hope they tweak that aspect a little, because as it stands, all of my characters look the same in the face. So, I'd like my characters to look different, rather than just the same man and woman at various stages of weight/muscle gain/loss.