Yes, I've also had similar experiences. I rarely get 2 business day delivery! Such a scam. The service is amazing only if it works nearly 100% of the time. Otherwise, you don't know if your Prime item will come in 2 days or 6 and it gets really hard to order some things with that uncertainty.
Curious where you guys live to have these experiences? I split my time between Minneapolis and Chicago, and have yet to have a (noticed at least) delayed Prime package.
Prime Now is even more insane. Last item I ordered arrived in 18 minutes from pressing the button.
I'm sure this happens, I just am wondering where one must live for it to be a common occurrence.