How to Choose the Right Mattress Firmness: Memory Foam vs. Spring vs. Hybrid Choosing a new mattress is one of the most important decisions you'll make for your sleep quality - yet most people don't know what they're looking for when they start shopping. Walk into any mattress store and you'll hear confusing terms: "firm", "medium", "plush", "memory foam", "inner spring", "hybrid". One salesperson swears by memory foam for back pain. Another insists springs are better for durability. A third says hybrids ar