Wow, you people must have seen some REALLY cheap adjustable stems or they were not properly greased (you have to grease the splines as they don't last long dry and may make noise) or something. I ride hard and am 240+ pounds. I bought mine to dial in the exact fit I need and will replace it. The ONLY issue I have is a tiny bit of play up and down if you jerk on the bars.
Would I want to ride with one the rest of my life? No. Do I find it annoying in any way? No. It's a tool!!!