[temac]

OS/2 might have been somehow better than Windows Consumer (and that's given the proper big enough computer at the time), but it was clearly inferior to NT. In term of tradeoffs though, maybe they are comparable (using the first versions of NT, maybe OS/2 needed slightly less resources, and we can put it between 3.1 and NT on the technical vs. resource usage tradeoff scale?)

BeOS made some terrible mistakes (gcc version depend C++ ABI, for example, and all of that at a time the C++ language was quite terrible) but was otherwise an interesting and refreshing OS, with cool ideas and goals.

NextSTEP was mainly just a Unix system with Objective-C framework in upper layers. It gave us OS X. Obviously it was superior to Consumer Windows (but that comparison again is strongly biased given it did not target the same computers at all), and it can be debated to hell whether it was superior or not to NT (depends on which aspect you care about, probably).