The primary advantage is that it saves two butt splices at the in-line fuse. I also assume that the factory spices are more efficient than my crimped spices in the field, so more power to the battery.
Additionally, it’s waterproof so I can put it in an exposed position as opposed to a weather protected position. This is a huge advantage in my situation because it facilitates maintenance at a more accessible location.
I added these to each string of solar panels as a safety precaution. The same waterproof connectors used on the Renogy panels make for easy installation. The internal fuses are replaceable.