Each feature can be enabled or disabled separately.
The language menu can be configured to show the browser languages only.

The extension works seamlessly together with the ‘Google-Preview’ Firefox extension.

Note 1: It may happen that the latest version is not yet available here (Addons need approval here and it seems that the AMO testers have pretty much to do).
So if you need an update and can’t get it here, try my homepage please:

http://netticat.ath.cx/extensions.html

Note 2: To use this addon with google.CO.UK (or other domains that match .*.*), the fixed version (1.67+) is needed.