NEHA

Some of those things:
The outside of the rotating assembly in a racing engine is moving at about 100 MPH. Depending on what measures are in place, the rotating assembly may carry 2-3 quarts around with it - this mess is often described as "windage". The engine's oil supply in a wet sump system lives 2-4 inches below this hurricane - even with baffles, screens, and trays to keep it in place, it is pretty easy to pump the sump out, and starve the engine for oil - especially under braking (in a V-8), when the oil from the top of the engine returns to the end away from the sump, through the timing chain and /or the rotating assembly.

Right, so the big tank prevents the motor from running dry on oil and the external pump scavenges oil and air out of the pan out of the pan which reduces windage. There is supposed to be a measurable increase in horsepower from the reduced windage.

To the vast majority the benefits are not seen to outweigh the problems. You need to find a location to mount the tank. You have to find room for the external multi-stage pump and drive setup for it. Then you have to deal with lot and lots of tubing and fittings. All the fittings of course want to leak. As Sherm says "Dry sump, wet floor". I once undid one line and thought it was OK since it wasn't leaking. I got a phone call and when I came back the entire tank (gallons!) had emptied onto the garage floor.

Dave Barry says things leak because they feel just you do when you have a full bladder. All they can think about is getting rid of the fluid. So when your car develops a major leak if you listen closely you should be able to hear it say "Ahhhhhhhh".