I know exactly how you feel. I did 24 FHD to 27 4K, was disappointed by the cost/reward ratio and then switched for a 34 UW 1440p and was blown away. But to get back on track and answer OP’s question: yes, you will notice immediately the difference between 1080p and 1440p for most games. If you mostly/only do competitive shooters, a high refresh 1080p would arguably be better. Also, please not that the CPU/GPU both play an important role at 1080p, but the higher the resolution the more the pressure on the GPU (even if the CPU is still relevant).