Soundex searches are options on many online search interfaces to databases and finding aids. Keep in mind that Soundex generally works best with names of Engilsh or Germanic origin. Soundex searches for Neill, bring up results of Newell, Neal, Nial, Neel, Nowel, Neil, etc. Some are more reasonable variants than others, but Soundex works fairly well on this last name.
There are problems with non-English names when Soundex searches are used. A Soundex search for Robidoux will not locate Robido, a very reasonable variant. French names are a good example where Soundex searches are sometimes week. There are other languages that present similar challenges to Soundex based searches.
Is the Soundex search option limiting your search?