I have attached a Dell Ultrasharp U2724D to it. Weight screen only, according to the data sheet: 4.5 kg.
It works very well!

I have a DELL U3011 9.3 kg (20.40 lb) on it and it works quite well. There is also an adjustment screw for the force of the gas lift, but I can't say whether it helps with lighter weights.

I'm not but it's solid

I don't know