I received this one as a replacement for an issue that the U4021QW I had displayed. It is refurbished, but it is a newer model, and of course, my warranty still applies, so many thanks to DELL. The 120hz compared to the 60hz of the 4021 makes a huge difference, a very pleasant screen for work. Also, the ambient sensor seems to work satisfactorily so far and has 3 options depending on the range you want it to operate in. A third very important difference for me is that it has more USB ports on the back, and in fact, one of them truly supports the highest USB speeds. To understand, with just one TB4 cable, the laptop outputs a signal of 5K2K/120HZ (and sound, of course) and accepts charging (140w instead of 90 on the 4021), ethernet, keyboard, mouse, camera, and an external NVME operates at a speed of 1GB read/write. On the 4021, the speeds with the disk were much lower on any port I had tried. It also has HDR and GSYNC, although I still haven't managed to get the latter to work properly. Finally, I should mention that on a MacBook Pro 14 with M3 Pro (11-core), it works perfectly at full resolution with just the TB4 cable. I believe it is worth the money considering we are talking about the top work monitor at this moment.

EDIT: I don't know why it says 90w charging in the description here on Skroutz; on Dell's page for the model and in the menu on my screen, it says 140.