The whole point of having a single adjustable upper control arm is that they're safer. They can't loosen themselves when you're going down the road and put you into a guardrail, or worse. Sure, it's slightly more effort when you set it up initially, but in reality, how often does anyone make adjustments after the initial setup.

On a race four-link or four-bar, you are always chasing a better set-up. On a street car, most of the time you get it set and forget about it.

you right it is safer, for a street rodder who never nut and bolt checks his car. they did not make there lower links adjustable at all, and 99% of the cars had the axle way closer to the front of the wheel well, then to the rear, and you were stuck with that.