How cumbersome is the content admin with 6 different languages
Have a look at the video about the localization feature on the Craft Feature page, this should give you a really good impression on how it works.

There's one thing though, that I'd really like to see improved: a way to see which content is still the same across all locales and a way to keep content of a field in sync after the first entry save. See this feature request: http://feedback.buildwithcraft.com/forums/285221-feature-requests/suggestions/7187381-better-options-to-sync-content-across-locales.

Altogether I really, really like how localization is done in Craft, it's actually the feature that made me aware of it (I had lots of trouble with Wordpress mulitsite etc.). And I'm also rather sure that we will see some nice improvement to it over time (Craft is still a new CMS).