Of course, people are a product of their education and cultural background. So "russian chicks are as any US chicks, unless they are fresh off the boat" is highly unlikely. Behavioral patterns may become the same or similar, as we all know that chicks behave strongly in accordance with their social circle. But that´s only the outside of a person.
On the other hand, it is a sad fact that emigrants often take on the worst of their new culture while trying to shed their cultural background. Emigration often brings out the worst in people. So my comment on russian chicks might be true for Russia, but might be only a part of the equation when it comes to emigrants. Food for thought though, I hope.
First, religion. While the Soviet Union was trying to suppress religion and many people grew up as atheists, not believing in god, there equally are many people around with deep christian beliefs. The Soviets completely failed in suppressing the church. While I am no expert in orthodox christianity, it does not seem to instill people with feelings of guilt about their sexuality, as i.e. catholicism does. So you generally can say that russian chicks are pretty pYssy generous, but this does not really depend on their religious background. I´ve had atheist ones and religous ones, no difference noted.. I guess their pYssy generousness comes from different factors. First, life in Russia was and is tough for many people, and sex, apart from alcohol etc., is a good way to get some light into your life. Secondly, sex is power, and Russian chicks know this better than any.
Russian chicks grow up in a society with traditional role models and almost no trace of feminism. They have not forgotten their female weapons and know how to use them. They want their men to be alpha, to lead and to decide. Many russian men I know are penultimate alphas - and they all have gorgeous women. So as a western wimp, you either can play sugar daddy and fork over money, or you have to come on all the alpha you can be, or you are history.
BTW a russian slang word for chicks is telega, which means cart or buggy. The guy is the one pulling and putting in the work and effort in pulling the cart along. Another one is tyolka - which means calf ))
This traditional role does not mean that russian chicks don´t make moves on their own, as Sav noted right on the mark. When they like you and want you, they don´t have any problems with coming on to you. You will know when they like you for sure.
As I said, Russia is a tough place for many, so most russian chicks are very street smart. They are forced to mature early, they early witness death and serious problems, and their toughness in life and difficult situations in life is phenomenal. This on the other hand means that they are probably tougher than you will ever be. So don´t relax too early..