So I've been thinking of buying a new larger monitor. My current one is 23" 1920x1080, and the one I'm thinking of buying is 27" 1920x1080. I don't want to go above that resolution cause I have a bunch of older games installed with resolution hacks/patches specifically for that resolution, so I don't want to mess them up.

Anyway, I'd like some opinions here, is 27" too big a size for 1920x1080? Would games look markedly worse because they're scaling over a larger screen size? Or would it be fine?

I usually buy Dell monitors because I've found them to be decent quality (never bought any of their other hardware though).

Assume you sit with your eyes about 20" from your present 23" screen. Lean forward 3". The pixels you see are now the same size* as they would be on a 27" monitor 20" away. Of course, this won't give you totally accurate feel for the larger monitor, but it might indicate whether or not your picture will look 'markedly worse'.

*angular size