I'm just an aircraft mechanic and pilot, but I've made a few observations over the years. For decades I was told that the low pressure on the upper surface of an airfoil creates the lift. This sole explanation never sat well with me, and I pondered it for many years. I remember as a kid making gobs of balsa wood gliders with a friend of mine. He showed me a glider that a friend of his father made (everyone I knew were pilots, aircraft owners, builders, etc.) that had a unique airfoil shape: forward of the main spar was normal, but aft of the spar, the upper trailing edge made a gentle "S" shape where it met with the lower trailing edge, and then both surfaces extended aft, parallel and attached to each other approximately another 20% chord aft. When I asked my friend why he gave it to him, he had said it didn't fly very well at all.
Fast forward to more recent years- A&P school, pilot training, and the airfoil shape stuck in the back of my head, and the Bernoulli principal thing just wasn't adding up. I kept thinking everyone talks of the airflow over a wing, but I reasoned that there is no airflow around the wing. The air is just sitting there, randomly moving about, then this wing of a certain shape quickly zooms by, and then the air is once again just sitting there. The air didn't flow over the wing, the wing moved through the air. The difference is subtle. What happened to the air after the wing passed by is important.
I finally found an article about a decade ago that addressed the very thing I was thinking: There's more to lift than low pressure. The article proceeded to explain that the low pressure on top of the wing only accounted for a percentage of the lift. The majority of the lift occurs when the mass of air over the upper surface of the wing is imparted a downward force by the tapering of the trailing edge as the wing passes through the relatively motionless air. This air has mass, and is accelerated downward: Ha! F=ma! I can live with that!
That explains why a high aspect ratio wing generates more lift for equal wing area then one of low aspect ratio.
The final selling point for me was when I considered a turbofan engine, specifically that of the Hawker Harrier jump jet. The bypass fan in the front of the engine generates most of the thrust for any turbofan engine (upwards of 80%). The fan blades themselves are nothing more than little high speed wings whirling around the shaft hub. The Harrier jet's forward lift nozzles on the fuselage pivot downward to direct this bypass air coming off the fan downwards and provide lift. (The rear nozzles include the engine exhaust.) If the lift off the fan blades was generated by the low pressure on top of the blades, wouldn't the jet then rotate its inlets up? but it doesn't.
So all this made sense to me, and explained why my childhood friends' glider wouldn't fly. The airflow off the back of the wing was redirected at the trailing edge to travel parallel with the direction of movement. No air moved downward, and no lift carried the wing upward.
So I think any vehicle attempting to generate lift by low pressure only will be almost impractical to make work.