I bought the UCDP monitor and am very satisfied. The UCDP has a slightly matt screen surface. Nevertheless, the colours and black levels are excellent. I use the monitor in my home office and game from time to time in bright and sometimes dark surroundings. I am not a fan of glossy monitors.

The two monitors ASUS ROG Swift PG32UCDP and PG32UCDM differ mainly in the panel technology used and some specific functions:

Panel technology:

- PG32UCDP:
Uses a WOLED panel (White OLED) from LG. This panel enables dual-mode operation: 4K resolution at 240 Hz or Full HD at 480 Hz.

- PG32UCDM:
Relies on a QD OLED panel (Quantum Dot OLED). This offers a 4K resolution with a refresh rate of 240 Hz.

Brightness:

- PG32UCDP: Achieves a maximum HDR peak brightness of up to 1,300 nits.

- PG32UCDM:
The exact HDR peak brightness is not specified, however it is known that QD OLED panels tend to have a lower peak brightness than WOLED panels.

Surface Coating:

- PG32UCDP:
Features a matte coating that reduces reflections, making it suitable for use in bright environments

- PG32UCDM:
Has a glossy coating that makes colours appear more vivid, but is more susceptible to reflections.

Additional functions:

- PG32UCDP:
Offers dual-mode operation at 480 Hz at Full HD resolution, which is particularly interesting for competitive gamers.

- PG32UCDM: Supports Dolby Vision for improved HDR content.

Both monitors offer 4K resolution and a refresh rate of 240 Hz, but differ in panel technology, brightness, surface coating and specific functions.

Conclusion for your use in bright environments:

The UCDP is less reflective and brighter, which makes it more suitable for your use!

The PG32UCDP is a better choice if you want the most responsive feel as it has a 1080p @ 480Hz mode, which the PG32UCDM lacks. It also works better in a room with quite a bit of ambient light, as deep blacks don't appear slightly purple like they do on the PG32UCDM. Finally, the PG32UCDP has better text clarity, so it's a better option if you want to use it for productivity work. However, if vibrant colours are important to you, the PG32UCDM is the better choice as it has more vivid colours in HDR.