I had an annoying pan gasket leak that would leak oil on the trailer floor between races. I had the header evac's on it the last 2 years.
Ran the car with the electric pump on yesterday and checked this morning and the floor is dry as a bone!
Also, I came back from a pass yesterday and noticed that the dipstick was blown out, and oil had leaked from the valve cover gasket on the pass side.
A further investigation found that the fuse holder that powers the vac pump lost contact and it wasn't running on that pass so yea, these things do make a difference!