Reallife szenario for GEQO

I am currently searching some resources, why and where the PostgreSQL 
GEQO-Engine improves large join queries. The theoretical background is 
clear, but i need some real life szenarios, where the GEQO-Engine beats 
other solutions. Have anyone made such a comparison, or have experiences 
which szenarios, where the GEQO has improved the query plan generation 
in contrast to "traditional" solutions? This will be very helpful (and 
interesting) ....

Thanks in advance,

   Bernd