There are a lot of words, even really simple ones, that it doesnt translate correctly. So it doesnt help a person who is serious about getting a correct translation. For example, in Spanish, "unos" should translate to "some." but it doesnt. It translates to "most," which is almost the opposite.
If you want a reliable source, buy a WEBSTERS SPANISH NEW WORLD DICTIONARY. Its the only truly reliable source, as web translators generally dont work. I got one for around $15 at Target.
Also, there needs to be different settings for American Spanish and "Spanish" Spanish (from spain) because the dialects are noticably different- which everyone that actually speaks Spanish knows.