Getting incorrect or messed up orders is just a part of e-commerce. It happens to all companies. Usually I won't judge a company for messing up an order, unless it's something that happens regularly. However, how they handle and correct the mistake, is what they get judged on.
So far, I haven't had any issues with it anything from ECS. All the ECS branded parts I've gotten have been fine, and no issues with any of the non-ECS stuff I've gotten from them.
So far, only vendor I've put on my "Avoid at all costs" list is CariD.