4K as 1440p, performance hit on Apple Silicon?

Hello! I’m in for a new 27” monitor and as I understand the majority of users prefer the look of a 4K monitor with 1440p HiDPI resolution to a native 1440p monitor non retina.

But how is the performance with the additional computing needed to do de 5K rendering and downscaling to 4K?

I’m very sensitive to sluggishness in the UI and I think that even the slightest lag should make me wanna go for a native 1440p instead.

What do you think? What are your experience?

The setup vill be used for VSCode, YouTube, and browsing.

Edit: Additional question, has anybody tried 4K@1440 HiDPI with 120 or 144Hz? What is your experience?