I moved to Berlin a couple of years ago and am gradually working my way around the estates, and have written in particular about the Britz estate here:

architectureinberlin.wordpress.com/2008/10/11/the-britz-horseshoe-estate-bruno-taut-martin-wagner/

I agree with Ian Cade's comment, that the estates can be a little underwhelming. I also feel that they wouldn't be my first choice of a place to live - not because of the quality of design, which is very high - but because they feel rather suburban and far from the centre of things.

Of course this is probably missing the point; it's the terrible slum conditions that these estates sought to replace which need to be considered. It's perhaps ironic that so many younger/wealthier Berliners choose to live in the high density older apartments of Prenzlauerberg, and more increasingly in areas such as Kreuzberg, many of which were built as working class Mietskeserne accomodation.