I use them for the name study I'm a member of and for finding people who have first names that are commonly misspelled.
I'm trying to think of the best example, but there are common spelling changes or mistakes that the search engine doesn't catch. So for Friedrich Tigges, for example, I would just search "Tigges" to pull them all up. I then sort alphabetically and I'm able to find if there's a Friedrich, Fredrick, Frederick, Fredrich, Fred, F, etc... with the dates I'm expecting. I'm able to find a profile I would have missed otherwise about 2-3% (ish) of the time I try this, which is a lot when I'm working on connecting profiles constantly. I don't think it's a matter of needing the search to be better/different, because sometimes the names are just too different.
Hopefully that made sense :)