So we upgraded our monitors here at work to high pixel density / HiDPI monitors. And it shows how useless photoshop is as a design tool. A 1,500 pixel wide design, created in photoshop at 72 DPI is the wrong size on retina monitors. You have to literally double the size, and double all font sizes to get it to work.
If you create a layout in Illustrator or sketch at 1,500 pixels wide..well then it's the right size..but none of your fonts will look how they actually look in a monitor. Pixel Preview mode in illustrator is horribly broken on HiDPI monitors, it just turns the design into a blurry mess.
Getting the new 27 inch HiDPI monitors is what pushed me to finally ditch photoshop. I now just use illustrator mostly as a sketch pad, and of course to edit my SVG images. I think a lot of people who rely on photoshop for design are in for a nasty surprise as they upgrade their monitors and find that all their PSDs are now useless.
In webflow, 1,500 pixels is exactly that, regardless of pixel density. And of course, all your typography is going to look exactly as it does on the web.