Not OP, but I got this one and really like it. There are plenty of cheap ones, but this one is really nice. I will say that I don’t use the puck much except to turn it on and off. I don’t really change the color temperature or brightness. https://www.amazon.com/gp/product/B07DP7RYXV/
My 34" ultrawide sits on the bridge of my desk above 4U height of 19" rackspace, is there much scope for angling the light about? Concerned that it might reflect on gear knobs. I otherwise really like what this does, quite a high price for some LEDs, but I have no doubt it's great...
It's not super adjustable, it's really designed to illuminate the area just below the monitor (mine is actually a 43" 4K TV). It defaults to sitting at 90 degrees - straight down. It can be adjusted a little bit, but ONLY towards the monitor. This isn't terribly useful - I don't know why you'd want to do that.
As for cost, yeah it's a bit much for what it is, but the build quality reflects that. The counterweight on the back is quite nice and solid feeling.
Yes. These all work roughly the same - the light bar rests on top of the monitor and has a counterweight in the back to keep it there. So no adhesives or clips.