When comparing Haiku vs AROS Desktop, the Slant community recommends Haiku for most people. In the question“What are the best End-User desktops for Desktop PC's?” Haiku is ranked 3rd while AROS Desktop is ranked 8th. The most important reason people chose Haiku is:
After about 6 years since the alpha version, beta has been released on Fri, 2018-09-28. Check [here](https://www.haiku-os.org/news/2018_09_28_haiku_r1_beta1/) for release notes.
Ranked in these QuestionsQuestion Ranking
Pro Beta has been released
After about 6 years since the alpha version, beta has been released on Fri, 2018-09-28. Check here for release notes.
Pro Ported to many platforms
Works on: x86, amd64, PowerPC, m68k & ARM.
Pro Amiga compatible
Can run OLD Amiga software.
Con No one uses it
It's a very niche OS that no one uses.
Con Small community
It is important when developing to be familiar with tools that other developers use. You can make any utility in any language you feel like, but if it's in an esoteric language that no one can read targeting a small platform that no one uses, then it was just something you did as a hobbyist, not as a developer.
This is not to say that Haiku isn't a great operating system to hack around on. Just don't delude yourself into thinking you're doing it to get familiar with tools that you need to know to be a better developer.
It's still in beta and quite unstable. Making it unsuitable for developing applications of any kind.
Con Limited hardware support
Hardware support is limited and you often have trouble getting even a printer to work.