I had wanted to buy a monitor mount for a very, very long time, but I never got around to it. Until now. What a relief for your desk! You gain a lot of space, your desk suddenly looks much neater and it even looks professional. Really w-a-u-w! Best (underestimated) purchase in a long time as far as I'm concerned!
The first thing I also noticed about the bracket when I unpacked it was how robust it is built. This is definitely not cheap crap, but a very solid and well finished construction!
I currently have 2 x 24 inch screens on it. One in landscape mode and one in portrait mode. I even clamped my desk lamp to one of the horizontal arms, because clamped directly to the table, my desk lamp didn't rise above my monitors. With the lamp on the bracket she even got a bigger reach :)
There are some clips for cable management at the bottom of the arms. I think it's a shame that there are no clips on the vertical axis. That really wouldn't have made the bracket more expensive. Luckily I have a roll of black, double-sided Velcro, so that was quickly solved.
Height adjustment is indeed only possible with an Allen key, but I personally find that a negligible disadvantage, because once the height is set correctly, you normally won't change it. Also, a different system for height control would almost certainly make the bracket a lot more expensive. Instead of another system for height adjustment, I would rather see the possibility to adjust both arms separately in height, but that would of course also increase the cost price.