My entire experience with Core Gravel was an overall pleasure. I had a fairly technical application with undulating terrain and serious drainage issues. Caroline showed great patience in answering my questions while I worked out the sometimes challenging procedures of getting the mats to mold to the terrain. I found that if you want the mats to melt into uneven terrain, it's helpful to lay them in the sun to warm prior to laying them. Furthermore, I found that it was helpful to lay one mat, fill with gravel, and then lay another in the really tricky terrain. My driveway now exceeds all preconceived expectations!