Both systems work together for maximum performance. The existing dry insulation is also saved. Renewal can cost less than the original, even after 10 years.
Costs are comparable to any good roof.
The net is more roof for the dollar. Some phases may be expensed as maintenance. The complete roof restoration can be spread out over a number of years freeing up capital for other projects or investments. Unaffected by grease or other common industrial chemicals. Will withstand moderate traffic without additional protection.