Just started a "Savage Species" party into 'City of the Spider Queen' last Friday. All 10th level, we have a Trumpet Archon (10th level), Treant (10), Centaur(6)/Fighter 4, two Trolls (10), and a Grey elf (with a grey elf cohort). Managed to kill off the cohort on the first encounter. Centaur (my daughter) didn't feel like playing, so after the first fight she's not with the party any more.
Making the characters was more fun than DM'ing them through the module (so far). My son almost played a Satyr7/Monk3, but changed to Trolll10 at the last minute.