Spring Count: A higher number of springs generally indicates better, more precise support. Look for descriptions like "high-density" pocket springs.

Layering: The spring unit is almost never used alone. In a premium sofa, it will be topped with a combination of high-resiliency foam and sometimes a layer of down or synthetic fiber for immediate softness and plushness. This combination is the hallmark of top-tier comfort.

Edge Support: Check if the perimeter of the seat has reinforced springs or a firmer border to prevent sagging when you sit on the edge.

The Sit Test: The true test is to sit on it. A good pocket spring sofa should feel supportive and firm, yet comfortably yielding. It should not feel like you are "bottoming out" onto the hard frame.