I canceled Prime over this ad thing, and what I noticed was they seem to ship packages as the same speed, but they let the order sit for a few days before fulfilling it. It makes it seem like they find the efficiencies from treating every package the same during packing and shipping worthwhile, so they just hold the order in a queue for a few days before releasing it as a punishment for not being a Prime user.
I could be reading that wrong, but it was sure how it looked with my first few non-Prime orders.
I have a warehouse serving our entire metro area five miles from my house. Shipping takes two days after Amazon sits on my order for 2-3 days.
Their drivers are also the worst. The driver that covers my area tends to throw packages a good 10 feet at my door. Needless to say, Amazon is pretty much my last choice option these days.
I could be reading that wrong, but it was sure how it looked with my first few non-Prime orders.