By driving less caster you will get a more aggressive car and faster response on the steering. But based on the increase weight transfer on the rear the rear axle can become a bit loose. With less caster you will get more steering off-power into the corner but have less steering on-power mid of the corner.

Tiny tracks with a lot of high angled corners mostly are good for less caster. Open and fast tracks prefer to have a car with more caster.