I've never run into a problem with EasyFind's performance, really. The newest version mentions improvements for both Tiger and Leopard, so I'd say this is a clear "Go!".
"Informative" might be the wrong word, I dunno. It's just that Spotlight doesn't like to find files by partial filenames. For example, you won't find "ThisFile_20090213.txt" if you're searching for "200902" in the filename. Spotlight only finds "parts" if they're at the beginning of words. You'll find "the" in a file named "this theatre.txt", but not in "this_theatre.txt" or "thistheatre.txt". Which, obviously, is a bug that hasn't been squashed since Spotlight came about.
(And no, Apple, I won't start using spaces in the names of files that go on a webserver.)