I love those buildings and live in one, couldn't be happier. Super nice view of the city, and very affordable since where I live many of those buildings still belong to the state.
One advantage many overlook is the amount of natural light, what a.o.t. has important benefits to the mental and physical health of the population. According to Wilfried Stallknecht (an architekt behind many projects in the GDR), the buldings should keep a distance that guaranteed that every appartment had, on the 22. February of the year, at least a room with 2 hours of sunlight. If you walk in those planned areas you see the huge space surrounding the buildings, with lots of green areas, parks, playgrounds and so on.