Hey brothers Monitor wise my knowledge is very limited so i need help, recently bought a GTX 1070 and now want to leave 1080P sicne more and more i notice the pixels on my 27'' and want to bump my screen size at the same time like a 32'' or 34''

I know that i could mostlikely max out 1440P with little to no compromise but 4K is out of question

if i buy a 4K monitor i am telling myself i will be ready for when 4K become doable on a single card with no compromises

first question would be is Gsync really worth it? i never had Gsync and doing some research on it it seems to only help if i am experiencing a lot of fluctuations in my frame rate which am not really unless i am running AA because of my low resolution, if it is worth it i guess that would narrow down my choice to a 1440P

second if i was to display 1440P or the max resolution i can achieve on my 1070 with no compromise on a 4K when gaming would it look or feel weird? i know upscalling makes an image more blurry but would it be really noticable?

personally don't care about wide screen or curved screen, i like the 16:9 ratio

TL;DR better to buy a 1440P monitor or is gaming on a 4K monitor at 1440P as good?

thanks for the help brothers!