I find the variable arc nozzles have a tendency to clog or develop gaps in the spray pattern. They also break easier. I don't believe they cover as well on the outer edge of the pattern. Meaning the right and left side of the spray pattern from the nozzel outward. But if you do regular maintenance of your system. Then maybe it wont be as much as a problem for you. I personally use them only when nothing else will cover. Good luck!
If I can't fix it, it's broken!