I think the new wikipedia-style translation interface is the way to go but I find my efforts are rewarded a little bit too richly in immersion mode versus lesson mode. Translating one sentence can get me ten points while taking only a fraction of the time a lesson takes, which also gives ten points. Calling for a more balanced weighting here.
They need translations so they heavily incentivize translation for users. Why not? If you don't want the rich reward you don't have to translate as much or at all.
In comparison with before immersion it's much easier to get points out of translations.