I've heard that Germans from the former DDR are a lot less friendly and outgoing than those from West Germany
I think so, based on my travels around the ex-DDR. It's usually most noticeable in smaller towns/villages - in West Germany, people are genuinely interested and curious in outsiders. I was there last summer for two weeks in a nice Rhineland village, and not only would locals always, always greet me, some of them would happily approach and ask questions, especially when they saw the Polish number plates on the car. I remember having a wonderful discussion with one older woman who spoke English with a beautiful American accent, as she'd been working for many years on a US base there. She wanted to know everything about life in Poland, she invited us for coffee, and she had very interesting stories about her life. Same story with the village pub - my German is hopelessly non-existent, yet I went for a beer there. I was treated very well and with a smile.
Ex-DDR? It just doesn't happen. They don't greet people (in fact, they rarely even walk around), they keep themselves to themselves, and the attitude is much more pessimistic. I know Frankfurt (Oder) very well, and there's a very clear divide between the ordinary people and those who work at Viadrina or in the public administration. If you go for a beer, there's clear resentment towards you (assumption being that you're Polish) if you don't speak German fluently.
My friend works in the German-Polish bilingual school there, and she says that it's a never ending battle with people from Frankfurt as they have such a huge chip on their shoulder. She's leading a campaign to make Polish a mandatory 2nd foreign language in FFO schools, but it's being met with hostility from many people.
