Better performance in general as you can benefit from parallelization.

Of course it will depend on the applications you run, the more multi-threaded, the better for more cores.

And also it will depend on the number of applications you run that can be scheduled to different cores. The more, the better.

For a simple analogy:

Imagine an 8 lane highway vs a say, 32 lane highway. Performance will depend on the number of cars that go there and their behavior.