I have had the same experience with ordering Whole Foods and Amazon Fresh in the bay area. Everything I order arrives.
I tried using a different grocery delivery and about 30% of what I ordered was out of stock. This was especially frustrating because delivery slots were in short supply here, so I felt rude making another small order immediately to fill in missing items. With WF/AF I at least know what is out of stock when making my order so I can choose my own substitutions or not bother trying to get ingredients for a recipe if something critical is missing.
While I didn't like the page divider in this demo, I also don't like having to see the screen whir by when you hit the space bar. Having the page flash past in the same direction you are trying to track with your eyes is not comfortable for me. I did really like the narrow width of the text here though.
I have noticed that reading on the kindle app on my phone is extremely comfortable, and it basically incorporates the things I just mentioned -- narrow column width and page turns that aren't disorienting. I know people hate pagination on the internet because it is associated with slow page loads, but fast pagination would be awesome.
I tried using a different grocery delivery and about 30% of what I ordered was out of stock. This was especially frustrating because delivery slots were in short supply here, so I felt rude making another small order immediately to fill in missing items. With WF/AF I at least know what is out of stock when making my order so I can choose my own substitutions or not bother trying to get ingredients for a recipe if something critical is missing.