Sounds great! There are so many beautiful cities that Russians can be proud of, but St Petersburg stands out as one of the most well-known ones.
Going by photographs, I think there are many cities in Germany that are more attractive than Berlin, but it does have some nice architecture of its own and seems like it would be an interesting city. It wouldn't be top of my list of places in Germany to visit, but I'd definitely want to see it.
I live in the UK, but I also have American citizenship, as my mother is American. So although I have lived my whole life in England, I have been to the US many times, and have a number of family living there.