The major benefit to a high-pressure system is the lighter weight of the guns. Tim Uhler and Kyle Davis find it is easier to clear jams, and there’s less reloading time with higher-capacity coil nailers. Most coil nailers are heavier due to the added nail weight, but the high-pressure guns are smaller and lighter to begin with.
The downside is that everything on a high-pressure system is expensive. The hoses cost more and need to be professionally repaired, due to the high pressure. The compressor is slow, but very quiet. It will (most of the time) keep up with two guys.