With FamilySearch, I find that the more info you have, as far as dates, locations, spouse names, the better the results are. Just a name won't bring back much, especially if there's a variation or error like the one you mentioned. I've found several records under names that barely resembled the one I searched for because I had the other data right. With Ancestry, I often get almost the same search results with just a name and their search seems to take those variations and errors into account.
I've been using both Ancestry.com and FamilySearch and find that they're both useful. Ancestry has pretty much every census record available, not just the data, while FS has documents that Ancestry just has the data on (vs. an image).