I use AppEngine for my experimental projects because I can get a simple data model and some handlers running in minutes and a (supposedly automatically scalable) useful backend up in less than a day, and at very low cost. (Virtually free if I use an *.appspot.com domain).
You do get lockin issues but don't you also get lockin from Heroku? Is there big advantages to Heroku that make it worth it?
AppEngine is a great tool for a great price. It scales smoothly with an affordable increase in pricing.
Heroku is sort of famous for getting too expensive at large scale. Their advantages are their ecosystem (most of the additional services listed in the OP can be installed quickly, and you're still only billed by Heroku), and their UIs which tend to be easy to understand and operate.
An instance on DigitalOcean would be more like 2 hours.
There's no lockin that I've experienced on Heroku.
Most of my time is spent consulting docs.
More generators than those will allow you to create reusable app templates which have these features so you don't have to repeat the (still very simple) configuration process for each app.
https://web.archive.org/web/20071105005403/http://heroku.com...
It's fairly likely they were working on them in parallel without knowledge of each other, though.