Purchased a new mattress and boxspring in June. The instructions say that you MUST use metal slats. The mattress was extremely uncomfortable because I was using "wood" slats. I purchased "Bed Beam" and it is the best sleep I have had in months! I know that you might be saying, "I cannot afford to spend this much money on bed slats." Bed Beam is worth every penny. Shop around - compare prices. If your new mattress is sagging, you probably just need good support under the box spring. It's the best money I have ever spent.