Each tool has its uses. A version of Tech Tool Pro comes with AppleCare, so Apple thinks well of it. DiskWarrior seems to work sometimes and not others. And TechTool seems to keep up quickly with changes to the OS (maybe that's because of the Cupertino connection).
However, I suggest instead of worrying first about tuning performance, you look at cloning your current system--files, applications and system--to an external drive. The whole thing. This is kinda like backup but makes a perfect image of your system. If you need to keep working, you can just boot from the external drive. No worry about licenses or permissions or reinstallation.
I use
SuperDuper! for this purpose and it works great. You can schedule it too.
I use a bus-powered FireWire/USB2 drive. After the first long clone, then the software just does the changes, much like an incremental backup.
daviD m.
(former editor of MacWEEK in the days)
Edited by davidmorgenstern, 07 April 2007 - 01:59 PM.