I haven't tried 1440p. I was considering it tho. But 1440p @ 60 Hz. Didn't sound enticing.
So I bought 144hz 1080p.
I would NOT go over 24 inches with a 1080p panel. Have not heard a single good thing about that. Pixelated image etc. So if you aim for 27 inch or something, I would seriously consider 1440p.
Btw, I can't stand 60 Hz anymore. Vsync lines are so annoying, even when web-browsing.