HttURLConnection vs Servlets

the Servlet topic has surfaced on the podcast recently but it hasn't 
been a main topic of discussion as far as I recall (or maybe I wasn't 
listening!) 
I've been collecting a few resources that might fuel a discussion. The 
reason for that is because I was trying to understand whether we 
should move from Restlet to Play! and the implications of that. 
Currently I'm developing on App Engine which is a Servlet container 
that uses Jetty. 
Restlet comes in various editions: the Java SE edition provides its 
own web server, the Java EE edition depends on servlet containers (via 
Restet's Servlet extenstion). 
The Play! framework doesn't use servlets at all but it can be deployed 
to servlet containers. 
For developing GAE applications, Play! uses a trick called the GAE 
proxy: http://www.playframework.org/modules/gae 
https://github.com/guillaumebort/play-gae 
The GAE proxy makes it possible for Play to implement hot code reload 
during development. 
Unfortunately GAE makes heavy use of servlets: a lot of services such 
as e-mail, task queues and chron jobs call into servlets that users 
have to implement. 
That means that without a servlet container those services are not 
available for testing, during development... unless one re-implements 
them on top of  HttpURLConnection, but am not sure if that's entirely 
possible. 
Back to HttpURLConnection, Servlet/Play and Greg Wilikins long before 
them have highlighted the limitations of the Servlet API. Here are 
some links: 
http://web.archive.org/web/20050308210733/http://www.mortbay.com/MB/l... 
http://blogs.webtide.com/gregw/2004/02/09/1076359560000.html 
http://blogs.webtide.com/gregw/2004/09/24/1096051860000.html 
http://www.restlet.org/about/introduction 
http://iam.guillaume.bort.fr/post/558830013/why-there-is-no-servlets-... 
http://www.lunatech-research.com/archives/2011/12/08/wrong-with-servl... 
http://theikester.wordpress.com/2010/05/07/can-the-play-framework-pla... 
Recently Tim Bray has posted an article "HttpURLConnection's Dark 
Secret" :-) 
http://www.tbray.org/ongoing/When/201x/2012/01/17/HttpURLConnection 
So it seems to me it's time to move away from the wrong type of 
abstractions and go back to understanding protocols, headers and 
scalability issues. So it's a chance to learn more not less!