Foe all I know, DiskWarrior does no optimization, but rather rebuilds the disk catalog. And when it comes to PlusOptimizer and TechTool Pro, they know no s**t about optimization, the only app that can do this properly is Norton Speed Disk. PlusOptimizer and TTP do defragment data but not files -> they place all data neatly in one chunk, but still the files are fragmented as hell, one bit here other there and so on...
Here's how I do: at regular intervals I boot in OS 9 which is located on other partition, defragment using Speed Disk (using profile specifically made for OS X) and then run DiskWarrior
Also, steer clear from Norton Utilities for OS X, several of my friends have had their disks screwed, experienced several Kernel Panics all because Norton. It's safe from OS 9 only. Also Norton Utilities 6.0.3 has bug in memory handling, stay at 6.0.2.