Malte, I'm not sure if spanish and german can be compared in this matter. What I know for sure though is that in german the gender neutral form is standard, even required, in a lot of contexts like NGOs and universities (unless it's only about professors of which the majority are still male unfortunately, at least where I studied).
I know that you don't mean it that way, but in your post it sounds like you are implying there is only choice between male/formal and a female/informal style. Let me emphasize that there is also a _gender neutral_ style in german, which won't sound annoying or informal if the translator applies a little thought and stays coherent.
I'm working on a site for a free radio, on which it would be unthinkable to use the old fashioned male form, and I think that is not the only project with this requirement. I think the conclusion of the related discussion on dotlrn translation was to avoid gender specific phrases whenever possible, but I can't remember what has been decided for those cases where it's not possible to avoid - I sincerely hope that we use a neutral form for those.