I love the admin-free nature of GAE, that's why I started using it in the first place.
"Infinite, automatic scaling" is a double-edged sword given the pricing model. Virtually anyone using GAE should be putting very finite caps on their resource usage lest they get a sudden spike of hn/reddit/whatever traffic that results in a usage bill that matches up with the "infinite" scaling GAE did for you.
Well, in fact anyone should ensure a positive ROI for visits, otherwise no visit is cost-effective after the free tier. If you make more than you spend per visit, you don't need limits and the infinite scaling capability is a godsend.
"Infinite, automatic scaling" is a double-edged sword given the pricing model. Virtually anyone using GAE should be putting very finite caps on their resource usage lest they get a sudden spike of hn/reddit/whatever traffic that results in a usage bill that matches up with the "infinite" scaling GAE did for you.