It was ok. Back when I ran BeOS as my primary OS (2001 or so) I built half a C++ web application on BeOS, the other half on a HP-UX server logged in through an X terminal using ftp to sync between the two. Not much support in the wider *nix ecosystem though, so anything big would often fail to build.

I regretted having to move away from BeOS, it was by far the most pleasant OS I’ve used, but the lack of hardware and software support killed it.