Which is more impressive -- finishing a PhD in 2.5 years or getting more research done?

I am working on a PhD in chemical engineering, and my advisor mentioned to me today that I'm on track to finish in about half a year. I only have one class left to fulfill the course requirements and I have a few papers published, with a couple more almost finished.

Personally, I'm in no hurry. I love grad school and working on research. However, from the perspective of a getting a good job, would a PhD at 23-24 years of age or additional research publications in high quality journals look better? Once I graduate I plan on either doing research in industry or working at a startup. I don't plan on going into academia.