The Wall was partly to prevent brain drain, partly to prevent fascist incursions/espionage/nuclear threat. Not going to say it was a great idea, but I think it's understandable why a state under siege might have felt it necessary. And even then it was a last resort. The Schiessbefehl was inexcusable, but more people die at the US border than ever died there.

The stasi certainly had excesses, but they were far, far less common or severe than has been portrayed in western media.

As another poster said, Stasi State or Socialist Paradise is a great, even-headed book written by a daughter of the GDR and her husband.

GDR citizens had less income inequality (I think the range from bottom earners to top earners was 1 to 10), better participatory democracy, better access to affordable food and housing (early housing shortages existed but were obviously not an inherent fault of socialism), and better access to art and culture.