Just more things to break. I have seen several with Model X doors with issues opening. I am glad my S does not have them.
Sure, it can break, but Tesla has done a good job so far improvING the reliability. I've had my X for a month and a half and they work flawlessly. You really get used to it, so much that stepping in a car without selfpresenting feels weird and old. It's the kind of option you don't think you need til you get it. I'd love the S to have this.
This is also covered by the warranty so like anything, you should be good to go for a while.