Been using a 27' 1440 for the last 5 years at work, and I can never go back to anything lower.
For games, however, 1440 has ~80 more pixels than 1080 which will reduce your fps by 80% given the same settings.
The higher rez is obviously less noticeable in games IMO.
The question you'll have to answer is which do you prefer:
-Lower resolution at max quality.
-Higher resolution and lower quality.
-Spend significantly more on gfx and have both.