You mean the IEEE 1394 Firewire drivers? Or the drivers for your interface?
Here is a video I made a long while ago when it was necessary to use the Legacy driver, Since 8.0.4 the default driver worked best for me (LSI in my case when using the integrated port, or TI when using the Firewire card, your driver will vary depending on what you are using)
http://www.vimeo.com/7355951
Pro Tools Drivers:
Driver Downloads and Updates for Pro Tools 9 and 8
If you are just updating to the latest PT drivers, then you should be fine, unless you are currently set on Legacy, then you may find better stability using whatever the "brand name" default driver is. But this can vary on each system, try them all, and use what is best.