I've heard similar horror stories from people in the Bay Area, but Amazon is almost always on time for me in Portland. The few times I've had a delayed delivery it's been either weather-related or because a USPS weekend carrier missed the delivery.
When USPS misses an Amazon delivery they claim they couldn't access the delivery location, which is laughable since my house is at the corner of two public streets and there's no fence between the street and the door. I assume they claim that to avoid getting dinged by Amazon for a late delivery. I haven't complained though, since I've read the USPS is seriously overworking their carriers with Amazon deliveries.
My only complaint about the Amazon Logistics delivery people is that they always leave boxes in plain view on my front porch instead of in the less visible covered breezeway near my side door. My weekday USPS mail carrier, UPS, and FedEx all know to deliver to the side door where boxes are less visible from the street, but Amazon doesn't provide any way to tell their delivery people to do that, and it's a different person every time.