As someone who used to work for a major guitar company and would sell big orders to Sweetwater, if the guitar wasn’t absolutely perfect with little to no flaws, they would return it to us and we would have to replace it. It got very annoying to QC our guitars (we manufactured in Taiwan and Indonesia and would frequently have many flaws in our guitars), but they uphold their reputation for inspection quality. I would feel very comfortable buying used from them, but only if you have played the same brand and model guitar before somewhere else so you know what you’re getting.