The V-173 flew well because it was lightweight enough to fly well. The XF5U was much heavier and more powerful and never flew. Due to its weight, it was not going to be STOLE in the same way as the V-173, nor would it fly fast like Navy jets that were enabled by the invention of the catapult launch.Was just looking at the Vought `V-173 flying pancake and saw that it had almost identical performance to a Cessna 172 despite having far better takeoff and landing characteristics. In fact, it has extreme STOL capabilities.
It also has extremely good forward and downward angle of view, and HUGE internal volume.
It seems to me that this layout would make an outstanding cargo or utility aircraft. And may be a good candidate for the new generation of hybrid engines, as volume and engine placement are not a restriction.
Low aspect ratio aircraft work well when the aircraft is light enough. Make them heavy, and it may well end up on the bad designs list, especially if underpowered as well. Because of the low-aspect ratio, the wing loading will be in a completely different category from typical aircraft designs. If you can maintain a similar span loading and power loading to traditional designs, it will likely perform similar to the traditional designs.
Barnaby's Facetmobile is a good example. It is a low AR design but it's span loading was similar to other small 503 powered aircraft. This was accomplished via a strong lightweight internal truss frame with fabric covering. This kept the weight low even thought the plane's skin area was very large compared to traditional designs.
V-173 was wood and fabric. The XF5U was metal stressed skin with large area; that makes it heavy.
Keep your design light with reasonable span and power loading, and you will likely fare well. Adding a couple counter rotating helicopter blades for propulsion and the STOL performance will likely grab attention.
PS - I'll note that configuring those 2 helicopter blades Chinook style may not grab attention as well, but may actually make for a more useful and practical STOL aircraft.