I went from 2x21" (1920 x 1080) to a single 43" 4K
I now have 4 x the pixel space and really, really close to the same physical window/font sizes. I could've gone slightly smaller, maybe 39-40", but a lot of folks go for a 4K monitor, then everything is so small they start futzing about with scaling to make stuff bigger and then complain that SONAR isn't vector based.
I could NEVA go back!!
Wanna see a screen cap? OK - look ma, no screen cracks!
((I actually have 5x the space 'cause one of the 21" is off to the side for pdf, monitoring, whatever.))