Debian Testing kinda sucks, it’s like the worst of both worlds of Debian and Arch; updates for some packages can be held back for months because of some blocker, while stable at least gets fastracked to important fixes for security or system stability, and Sid just naturally gets them faster because it’s more up to date. Sid is probably better overall, but why use an unstable rolling release without all the convenience that Arch’s tools offer? AFAIK pacman is really nice for stuff like making your own packages. Plus it has a much larger user base than Debian Sid, which helps when you’re looking for a fix for recent issues.