The way I figure, whichever method you use, to move the tarp, you have to go to both ends. So (in my mind) the argument that it's simpler to move 2 prussiks vs. adjust 2 ends is rather null. Whatever, HYOT (hang your own tarp).
I've always used Linelocs, and they're dead simple to use, and I've only ever broken one, even in quite high winds, and that was my own fault.

Of the 2-ended camp,
PF