For gaming, 120Hz is really nice and once you've tried it, 60Hz doesn't feel smooth. For desktop stuff/work, then resolution is important. 60Hz @ 2160p is enough then, imo.
What do you do for a living?
If you do anything CAD and part design/manufacture then resolution.
If you only use the pc for leisure then refresh rate.
If you do image editing/photography/movies then ignore both and choose the panel with the best colour accuracy.
Capontes, Actually I use all 3 of this xP
Fusion 360 - check
Photoshop - check
Overwatch - check
Actually Im think about LG 27GN950 (4k 144hz), but dont know if 27 is not to small, and if color accuracy is not to low ;p