Thanks for the kind words (and the purchase) ... a portion of tonights pizza in your honor my friend.
Updated the httpbin.org ... thanks for that
Flash memory is external to the physical ESP8266 ... RAM is internal. Different board makers add different sized Flash.
Starting page 28 are different module breakdowns but what I think I need to do is put together a summary table showing their different characteristics.
I have an ESP32 now and plan to update in depth on that. I have been quiet for a few weeks now as most of my time has been spent putting the polish to a Raspberry Pi book ... however, as a result of that, I now have a ton of stuff to explain on more peripheral integration with the ESP8266. I have chosen to do one at a time otherwise I get to neither. The Pi stuff will end Feb 1st and then back into ESP land.
Looking forward to ongoing new content in the years ahead.