[Macha]

1080p at 15" = 140 DPI

1440p at 27" = 100 DPI

I'd expect better text clarity on the 1080p laptop screen, whether you keep the same pixel size or adjust for similar physical size. The real tradeoff you're making is how much you can fit on screen.

[asadkn]

Technically correct. But practically the perceived PPI/DPI would matter more, with distance. Relevant: https://tonsky.me/blog/monitors/#the-myth-of-apple-patented-...

[teleforce]

Yes, thank you very much for the explanations!

It seems to my eyes that even with 10" devices with 1080p display, my six years old 27" display with 1440p is much better to work with than 1080p of the much smaller devices. I guess we need a more objective definition of Quality of Experience (QoE) for display quality to avoid being duped by the manufacturers.