When you play metal music, you often find yourself in various drop tunings - in my case a drop c. Without this particular set from Daddario, I would have to either buy some much more expensive custom sets, or butcher 2 other sets to not have horribly inbalanced strings, some either too taught or too floppy.
Daddario always have a nice quality compared to the rather low price, and the only complaint I have is to the company, not the product, that they really ought to make this set in other gauges as well, as they are just on the thin side for drop c (which is a rather popular tuning) for my liking, at least for a regular 34 inch scale bass. Something like 55-75-95-125 from Daddario would be the dream. But these are still very good for the price.