Is it worth dishing out for a 4k monitor or is a 1440p one just as good? (Currently on 1080) I currently have a 27" 1080 monitor. I'm looking to upgrade to either a 1440p monitor or if it's really worth the extra money a 4k one. Also I currently have a evga gtx 780. Will that be fine with both resolutions? 

Cheers guys 

Ps uk surgestion for monitors would be very welcome 