Are briquets more consistent to cook with than lump?

Yes, by nature of their manufacturing process, briquets are designed for a consistent grilling experience. When first opening a bag of charcoal, you see the uniform briquets. In contrast, with lump there could be pieces of vastly different size and shape. Moreover, the char and other ingredients in briquets are specifically designed to provide the same amount of cooking time at an appropriate temperature in every single bag.