I'm amazed with the improvement in Turkish. Here's an example:

http://i.imgur.com/NQvJ6bK.png

Left side is human translation, right side is Google:

http://i.imgur.com/bYJDHhs.png

The loss of information is minimal, and mistakes are very tolerable. Funnily, the biggest ones are already underlined by Chrome spell checker.

update: I'm trying it with my commit logs (English -> Turkish and German) and the results are amazing.