Can't decide on a monitor

[MasterCalaelen]

I've been looking at all sorts of monitors for a while now and I can't seem to decide on one.

The main issue is that I can't decide on whether I want a 24" or a 27". I've always had a 27" monitor in mind long before I got serious about a new computer, but didn't do any research into it at the time.

Is a 27" monitor with a maximum resolution of 1920x1080 worth it, or will you notice the image becoming less sharp and smooth in certain scenarios? If 2560x1600 is sort of required for a 27" than I can just stop looking into them. I was looking at something like that Asus VE278Q if I were to go with a 27".

The 24" I had in mind is the Dell UltraSharp 2412M which in all honesty seems perfect in all departments, short of the response time which would've been better at 5ms or lower but not a deal breaker since my current monitor is 8ms as well and I've never noticed any lag/ghosting/tearing. One thing is that it's got a resolution of 1920x1200, would this cause any issues for gaming or watching movies?

Price range is € 300,- and the use would be for gaming, watching movies, PhotoShop work and some video editing.

The logical side in me says the UltraSharp is a better buy, but I can't shake the feeling that I'd regret not getting a 27" especially because I'd be watching a lot of movies/shows on it, even though a 24" would be a huge upgrade from my current 4:3 19".

Hoping someone here has any experience with either monitor or can talk some sense into me if I'm leaning towards a wrong decision.