Cards are very similar, neither of them are really for 1440p gaming though, they are for playing 1080p at max settings.
To play at 1440p you will have to turn settings down a bit.
If you use adobe creative suite software (photoshop, lightroom, aftereffects, illustrator, etc) or if you do video editing, 3d modeling, etc, then you to get NVIDIA card as most content creation software can utilize CUDA cores in NVIDIA hardware.
If using only for gaming then it is a pretty dead even comparison in real world performance.