[PSS]

What LS compresses is defined by "Compressible Types" parameter. By default this includes text files, javascript and xml files.

I find it simplest to use both static and dynamic LS compression and set compression off in apps (like Vbulletin). The compression effect is same:

(gzip level 9 in both, Firefox)
Vbulletin front page with internal compression: 11,13 KB (11 395 bytes)
Vbulletin front page with Litespeed compression: 11,13 KB (11 393 bytes)

Why make PHP do the work LS can do. And LS compression works with all apps, even if progammer did not use ob_start("ob_gzhandler") or send proprietary headers for some reason.