Astonishing good for general vocabular, even for less frequent standing expressions. Time saving is typically lower for professional quality translators, but high for occasional translators of own text. The latter ones carry the meaning and the intentions in their mind and accept that the contents may vary betwenn translations or that formulations are not optimized. So occasional translaters better benefit from reduced typing work. French 'serveur Internet' became the English 'Internet waiter' instead of 'Internet server'.
Most errors are limited to style and grammer.
There is no better solution than machine translation for most tasks. Click here on 'Altavista', click there on 'translation' Text Translation. Altavista has a click button for the translation of Web pages. Once in the translation page, you can type in any Web address, to receive instant display of the translation. Altavista hat eine bersetzfunktion.