Both these cars have a very good reputation (and results) as racers featuring American V8s and pure racing car components. They should be very interesting cars to drive.
Pure sports prototype chassis combined with the reliability/maintenance cost of American V8s.
Certainly not practical cars to haul around, with those big diffusers and what not.
But then you have an F50 to compare...
... racing, it's life. Anything that happens before or after is just waiting... (Steve McQueen / Le Mans)