We have one of these as our 'TV', just projected onto a white wall. The main advantage it has over a large TV is that it's easy to move. Disadvantages are that it is lower resolution, although it's fine for home entertainment. 1080p is on the low end for a productive work monitor.

This particular projector has a very short throw, so you can get a massive screen from just a few feet away. But the larger the screen the less bright it will be and the darker you'll need to make the room, which can limit its use during the day.

It's also a reliable source of heat, which can be an issue depending on the season.

At this point you can get quite decent 4k projectors for around $1000. Also usable during the day (though less ideal). For us it was the difference between 3000 and 4000 lumens. Pretty silent too.

We also have been using short throw projector instead of a TV for at least 10 years. An obvious advantage is that the screen size can be huge, but as you mentioned on the down side this means that you need a relatively dark room. Also, there is a fan noise, which is not much of an issue if you are watching Terminator 3 on full volume with subwoofer turned on, but may be annoying if you are working in a silent environment.