I have a 24" FullHD monitor next to a MBP 15". The picture on the former is so poor compared to the latter that I only use it for reading email and web browsing, and do all the code work on the 15" high-DPI screen.

Under Linux, situation is not as bad, since you can persuade xft to optimize font rasterization for readability. OSX makes the choice towards glyph shape fidelity, though, even at lower point sizes, which results in horrible anti-aliasing blur.

Possibly related: some Macs render terribly blurry text when the monitor color profile is not to their liking--look for the "sRBG" toggle, and toggle it.

Especially so when using HDMI, Macbook often thinks it's a TV. You might want to google patch-edid

Wow. I wonder if it's a part of common lore which I was somehow oblivious of.

I use curved 55" UHD from Samsung as a TV/monitor; you need to keep your distance from it as being very close the picture is a bit weird (first you need to turn your whole head as it's too much for eye movement only, second there are wide FOV distortions; like when you put your head close to a normal monitor). The dynamic range is much lower than EIZO/LG pro monitors, colors are washed out; generally, it's fine for SteamBox and playing games and as a real-world preview of how a movie/photo would look like on a real consumer device, but you won't get anywhere near pro quality a proper monitor gives you (even when you enforce 4:4:4 mode instead of default 4:2:2). I have 3x 4k displays (30.5", 28" and 55"), can't go lower than 30" now...

I got the Samsung 49" 8500. Highly recommend for coding.

That doesn't come in a curve does it? Since I want to layout the desktop similar to a multi-monitor setup I figure the curve will help to angle the sides in. Do you find it awkward to look at windows far off to the side with a flat monitor that size?

8500 has a curved screen. It is definitely an improvement over a flat screen for looking to the side.

But I would want to sit twice as far away from the 48" screen, so that much pixel density isn't so necessary. (Actually, I have trouble actually picturing working on a 48" screen, the distance would be awkward...)

48 inches is a far off distance from the screen, I think you'd typically be in the 20"-30" range

He wasn't referring to the distance away from the screen, but rather the size of the screen -- if you quadruple the area of the screen from 24 inches to 48 inches and also quadruple the number of pixels then there are the same number of pixels per unit area, which means if you get a larger screen and it is too large, just use a subset of it and you can emulate any smaller-sized screen without having larger pixels.

Exactly. It should be like having multiple monitors. I would never run an app at full screen on that.

Ah, gotcha. I misinterpreted there.