A spring core will maintain the look over a longer time as it will not break down like foam will. The only con to the spring is they are typically not as firm as a foam cushion can be. So if you are looking for a firm seat that will hold its� shape over the years you would want to go with the densest foam you can buy and will typically be looking at a custom company for this type of offering ( IE Bassett or higher). If you want a seat with more give then go with the springs as they are far less susceptible to wearing down and you can get these in mid line furniture (Jackson Furniture or higher). With most of you low end companies, if they offer springs, use a cheap spring that will not hold up and the foam they use is cheap. They cut corners to keep the cost down.