The main difference between U3223QE Vs P3223QE is that the "U3223QE" version offers an IPS Black display; while the other doesn't. IPS Black technology provides 35% deeper black than conventional IPS, so that it enables sharper expression.

At the same white luminance of 400nit, the black luminance of conventional IPS and IPS black (> 2,000:1) varies by approximately 0.1 nit.

That is the reason it is offered at a premium over the P3223QE.

There are few other differences -

• Additional ports (two extra USB 3.2 type A's, one audio line-out port, one displayport out port, and two extra Type C's, one C port is used as upstream to hook up to a computer, the other as downstream for peripherals)

• Ability to daisy chain another monitor via the DisplayPort out port.

• Built-in KVM switch to hook up two computers to one set of peripherals + monitor (w/ KVM) itself.

• Split-view of two video-in sources, or "Picture-in-picture" mode.

If you don't use multiple monitors - you won't find a difference. If you are willing to compromise on the monitor size, look at Dell UltraSharp U2723QE - it's got everything you'd want.

Adding to my previous response.

Frankly speaking, the difference between IPS and IPS Black may not be very relevant for people who use computers for non-design tasks, such as coding, document creation.

The text looks crip on both panels; but scenes with black background may show a noticeable difference.

Main drawbacks of IPS panels is that they often have inferior black levels and lower contrast ratios compared to other panel technologies, such as VA (Vertical Alignment) panels.

This means that black colors may appear slightly gray or washed out, especially in dark environments.

If you can deal with that; don't spend $100-$120 bucks more.

Update:

I've bought the Dell U2723QE Monitor and been using it as my daily driver for the past 1 month. Here are few main points of my review:-

1. The display is better than I expected. The text is crisp and I have no problems.
2. No need to worry about the 4K scaling on MacOS. Everything works fine.
3. The biggest advantage of this monitor is the stand it comes with. It offers height adjustment, tilt adjustment. I use these more frequently than I initially imagined. I couldn't be happier.
4. The number of ports is very handy. I have already attached PreSonus 3.5" monitors, a cable to charge my phone and another cable to charge my smartwatch.
5. Price: This monitor is 33.33% price of the Apple Studio Monitor with more features and functionality.

I think I couldn't ask for more. Super happy with my Dell Ultrasharp U2723QE. Would happily recommend to anyone looking for a good monitor.