3D/4D Scans Freak Me Out

Rikki Dee
My mother-in-law asked us to get one when are able to... it seems invasive (Update: Before I alarm anyone else with that word. I don't mean in a harmful, penetrating or surgical way. The word can mean a few things. I used the term loosely).
We weren't planning on it. I've seen some pretty creepy ones. It's my baby so I'll look at her (20% chance it's a boy) the rest of my life and I'm sure she'll be gorgeous!! Are there other benefits to this type of scan? Or do you just wanna see who baby looks like?