I'd always used the so-called "bumper" cam in every GT game since the first one, but there was a licence test at Le Mans in GT7 where I was terrible at it, and when I switched to chase cam it was a revelation. The particular car had a very low bumper cam, because of how low the driver is in that car, and I just couldn't see the shapes of the corners well enough to judge when to turn. I was immediately massively faster with chase cam, I could so much more accurately follow a good line through the corners. I've stuck with chase cam ever since, though I think bumper cam is fine for cars where it isn't so close to the ground.