[calmbonsai]

Please lookup the flight envelope, cruise fuel utilization, and stall characteristics of the Dyke Delta along with its cargo capacity.

Then you'll understand why so many Cessna 172s were built.

[jtrip]

It wasn't more fuel efficient than the standard plane? Was it because of the propeller up front?

[calmbonsai]

It was more fuel efficient only over a very narrow band of the entire flight envelope. Also, it suffered from snap-stalls and very poor stall recovery due to its delta wing.

This is, primarily, why you only see delta wings used in super-sonic aircraft where these limitations are more than made-up for its ability to go trans-sonic with (relative) thrust efficiency.