Was a linux distro that's "source based" (i.e. no package manager) even a viable choice for real world server / desktop setup?
Edit, additionally, yes. Such distributions are suitable for essentially any task for which any other distribution is suitable. The primary caution that I would offer anyone when venturing away from RHEL/Debian is how much you trust whatever organization to still be around in five years. If you're comfortable managing everything yourself, pick whatever; otherwise, it's "safest" to choose something that either contractually will still be around (RHEL), or is governed in a way that ensures some continuity (Debian).