UltraFine 5K
Used by 12 peopleapple.com ↗

“I have it open on an arm, next to an LG 5k monitor with slight burn-in.”
Tim Van Damme Interview, Software designer (Gowalla) · via Uses This 
“I don't want the bulk of a 15" but have an LG 5K to plug in when I need real estate.”
Max Howell Interview, Developer (Homebrew) · via Uses This 

“At work, I use a 24" LG UltraFine 5K display, attached similarly via USB to my MacBook which sits on a Rain stand.”
Jesse Ditson Interview, Maker, musician, developer (Attic Labs) · via Uses This