Was a great decision to get to know SF, amazing city, I love it! Give my thanks also for Marc tips and from ...sorry, forgot her unusual name.... Valencia street was a important discover ;)
If Marc needs an apartment when he comes to Frankfurt, he can look up for the one I rent (Is shared with my office): https://www.airbnb.de/rooms/745165
Just he should avoid to come to the Book Fair time, is all pack and incredible expensive, even in Heidelberg!
Thank you for all!
Best wishes from Frankfurt