Serious question: What makes Arch's package manager so "great"? I always just found it confusing to use. The flags don't make any sense to me. It feels like you have to add a varying number of s or y to get it to do what you want. I never found it to be any faster or slower than any of the others (apart from portage of course) out there. And apart from the flags it doesn't seem to give me any more or less trouble than the others.
As a user it's definitely harder to get into than apt or dnf. However, as a packager, it's very easy to package new applications for pacman. That's also why the AUR offers this many packages often not found in other distros.
Dunno. Anecdotal, a few years ago pacman appeared to be much faster than apt-get for me. Currently I don't see that very much difference but then again I haven't paid much attention to it.
It's fast. That's why it's great. I've considered switching to opensuse a lot, but the speed of pacman compared to how slow zypper is always drags me back to arch
I've heard countless times it's one of the slowest package managers and the last time I tried opensuse it confirmed that, though that was a year ago, so I guess improvements have been made