All you need to know about EPM 11.1.2.3

Installing and Configuring EPM version 11.1.2.3

There are some significant changes in install/config tool too. Below link gives a detailed description of those changes.

http://john-goodwin.blogspot.in/2013/04/11123-installation-and-configuration.html

http://www.orahyplabs.com/2013/04/epm-11123-installation.html#.Uk-L4oZRBBk

http://www.in2hyperion.com/category/Hyperion-Enterprise-Performance-Management.aspx

New Features in 11.1.2.3
http://looksmarter.blogspot.in/2013/04/all-cool-new-features-in-oracle-epm.html

EPM 11.1.2.3 install/config screen shots Document:
http://in.linkedin.com/pub/venkata-apparao/20/4b5/13b/

Downlod it from my linked in profile.