Hi! I've created section about testing in project wiki page: http://wiki.postgresql.org/wiki/Fast_GiST_index_build_GSoC_2011#Testing_results Do you have any notes about table structure? As you can see I found that CPU usage might be much higher with gist_trgm_ops. I believe it's due to relatively expensive penalty method in that opclass. But, probably index build can be still faster when index doesn't fit cache even for gist_trgm_ops. Also with that opclass index quality is slightly worse but the difference is not dramatic.
------ With best regards, Alexander Korotkov.
