It's a very personal thing. Some people happily do it all day, others declare it a blurry mess. I'm somewhere in between. I enjoy doing stints of 1-2 hours in there just for a change of scenery and to help me focus. It's perfectly usable for me, but it's not as good as a real multimonitor setup in general.
A key element is that although the resolution is lower than a real monitor, you get to make the monitor bigger. So the limit ends up being when you start having to turn your head to see what's on the other side of the monitor, which sounds benign but is an ergonomic disaster.
The idea of this[1] working for me led me down a rabbit hole of all of the VR appliances in an effort to make it work.
For me, getting into the flow of programming is as much about the environment as it is anything else. Scenery, keyboard, mouse, desktop environment, form factor, etc. I am peculiar about all of it depending on context (collab space vs. in transit vs. coffee shop vs. at home hacking)
To have a device where I could be literally floating in space with all of the context surrounding me sounded like nirvana. Until you actually try it and the world is blurry, resolution is shitty, fonts look like garbage, etc.
I've settled for a very large ultra wide monitor - 5120x1440@240hz resolution which takes up ~3 screens worth of horizontal space without the bevel. If I could get one twice as tall pixel and physical dimension wise I'd buy it in a heartbeat.
>If I could get one twice as tall pixel and physical dimension wise I'd buy it in a heartbeat.
I can recommend using a 8k 55" TV as a monitor. They can sometimes be found for around 1000 USD and I am quite happy with mine after several years of use.
About arms-length. No curve, I run it at 175% scaling which at 55" makes everything large enough that even the corners are easily readable.
I used to run a 42" 4k monitor before this at 100% scaling, which made everything a little too small in the corners and I kinda wished it was curved, but with the 55 it's no problem.
A key element is that although the resolution is lower than a real monitor, you get to make the monitor bigger. So the limit ends up being when you start having to turn your head to see what's on the other side of the monitor, which sounds benign but is an ergonomic disaster.