Exactly, nginx stable is more like a LTS branch. See https://www.nginx.com/blog/nginx-1-6-1-7-released/ https://www.nginx.com/blog/nginx-1-6-1-7-released/ which

Exactly, nginx stable is more like a LTS branch. See https://www.nginx.com/blog/nginx-1-6-1-7-released/ https://www.nginx.com/blog/nginx-1-6-1-7-released/ which also mentions "Note that stable does not mean more reliable or more bug-free. In fact, the mainline is generally regarded as more reliable because we port all bug fixes to it, and not just critical fixes as for the stable branch. [..] We recommend that in general you deploy the NGINX mainline branch at all times."