I use mine as a continuously recirculating arm and a sparge arm. I've never had it clog, not on one hole. However, I have had gravity play interesting tricks on me.
When I sparge or recirculate, I have the liquid running quasi-slow through there. If it is slow enough, I'll notice that the sparge arm must be a little lower as it get further down the line. This is because of pressure drops and what not. That being said, at some point in most of my sparges, the flow rate is increased and water comes out every single hole no matter how it is placed. All in all, I've been very pleased with locline(been brewing a lot since I got my setup going with this arm). Another small problem I've had is it came apart while I was adjusting it at the beginning of a mash, but it was pretty easy to put back together on the fly, just hot. The quick disconnect valve I added clicks into the upper part of my mash tun and it super convenient. I'll remove the arm when I'm pouring grains and when I go to clean everything at the end. The outside is just a half-inch nipple, which is all the convenience I need on that side.