MTCs are medium chain tryglycerides. They are slightly lower in calories per gram compared to other fatty acids and their energy metabolism more closely resembles carbohydrate. The do not "store" as adipose tissue as quickly as fat.
I don't like them. For one thing, MTCs can effectively lower blood glucose in a typical supplemental dose. The big hope people had with supplemental MCTs was that they would provide a great endurance fuel. This has proved to be unfounded.
But if you're looking for a fat that is a more efficent fuel source than other fats, MTC is the ticket.
However, carbohydrate is still a more efficient fuel source than MCT.