Depends on what you need.

The one with lots of publications in big-deal journals may or may not be running a sweatshop. And they may or may not be doing actually interesting science, because that game requires so much attention to fashion, fundability and grinding out large quantities of papers (contrary to common belief, prestigious journals do not mean journals publishing the highest quality papers).

But if you want to learn that particular trade then find the advisor best at it to study under.