Here in Palm Beach County Florida, A/C contracters use the prefab concrete slabs in lieu of poured concrete. Most customers are not even aware of these slabs not being the "real deal" and being quite cheap and flimsy. I believe it's a combination of concrete and fiberglass and is fairly light (compared to solid concrete). I'm concerned that if the wind picked up enough in a very strong storm/hurricane, away goes the condenser and slab together. I have a 3 ton Trane XR15. Of course at that point, my roof might go the same route! Although hurricane straps are required in numerous Florida Counties, the slab itself is not very substantial. I know poured concrete is the way to go, but it will be a pain at this point to have it done. What do you guys think about the prefab? Does it do what it is intended to do to hold the condenser in place and structurally, should it last 10 years+?