The campaign was written to challenge optimized PCs at the end of 3.5 edition, so even with all the splatbooks. It was even more deadly then Age of Worms (much more actually).
The first four adventures of the campaign were nightmarish, the PCs were constantly butchered in very brutal ways. After that, death count slowed, optimizers could feel safe, but the illusion of safety led to catastrophe in a number of choke points. Underestimating the enemy could quickly result in a TPK, even at high levels.
The sheer difficulty of the campaign was very appreciated by the optimizers, which felt challenged and wanted to finish it at all costs.
This is the most cinematic of all D&D adventures I know of, you really really feel as a star in a movie during play. We actually chose the faces of Hollywood actors for PCs and NPCs (Gwynneth Paltrow was Lavinia, Brad Pitt was Vanthus...)
I love Savage Tide. My #2 best of all times, just a bit after Age of Worms.