1. Not a search engine. So you will not be able to see information from other forums, discussion boards, etc. unless cited by someone else on Quora.

2. Is a Q&A community so you will be limited to the experiences of the community. This can also result in community bias.

3. Is a site I would only consider to use as one of many sources for researching information.

4. Requires creating an account.

They also have an annoying history of hiding information found via searching in other search engines so I do not trust the company all that much. Whether or not that is a fair opinion is up to you, but that is why I would rather not sign up for an account there.