how is the 'special camps' different to regular camps which shukhov had been in previously?

There are different types of "special camps". Kilgas argues that though Shukhov has been in camps for eight years, they weren't "special" camps, out of which no one's ever come out alive. Shukhov remembers his seven years in the North, where any squad that failed to fill its timber-cutting quota was forced to stay in the forest after dark. Shukhov says that they have a quieter life in this "special" camp, where they go back to camp when their work shift is done and where they get three ounces more of bread than in the North. The numbers they're forced to wear don't weigh anything.