FreeBSD user here. I've always been curious about the ports-tree-based packaging systems found in these Linux distros. Is anyone familiar enough with both to offer a comparison?
I've only experimented with Arch, though, and I'd also like to hear from others who know both well.
For all practical purposes you are correct.
I personally think of Arch as a collection of components loosely put together, you pick and choose what you want and they generally work together, there are no releases per-se, stable or otherwise. OBSD is a more coherently designed and engineered system, if you want a particular feature that is available in a new release , the logical way to get it is to update to a new release. If you don't want it , you can simply stay on your release and just apply the rare security patches that come through.