I would be way, way skeptical!!! I know a little about masonry work and this doesn't sound quite right.

How do they "kill" the edges of the overlay? How thick is the overlay? I'm sure they can do something that will look good initially but I can't imagine anything holding up for a period of time. I would ask them to show you a job that is at least two-three seasons old.

Concrete (almost all masonry) has great compressive strength but very little tensile strength (flex). If it is allowed to move even the slightest, it cracks very easily. I may learn something new on this one but I can't imagine how, for that price, they could give you a long-term solution.

Dave S.