Earlier in the summer we posted a wiki page for several customers who were playing with the Advance Toolchain.
Check out
How to use Advance Toolchain for Linux on POWER
We have found the Advance Toolchain easy to install and use. We recommend it often to customers who are looking for pieces of the software stack which are newer / more recent than what's shipping in the distros.
Let us know if you've tried Advance Toolchain recently to improve performance of your application. We're looking to better understand the challenges of performance tunings and improvements for customers using Linux on Power.