I should disclose I received a membership in exchange for a little work I did for Ancestry, so I'm not out of pocket for my access. But I find it pretty useful to have, not just for impressing relatives and in-laws with all I can find about the family tree, but just as much in historical work. For searching out biographical, birthplace, residence, and family details of all kinds of people, it's very effective.
The sources Ancestry and sites like it offer access to are generally available from public archives, even online. It's not like you can't get this data any other way. But for the fee, they do add a lot of organization, convenience, and searchability. But right now you can try out the 1891 material and see what you think.
