Arch is excellent, and seems to have gained a lot of visibility/users in the past few years. And it's a great way to learn. But it is not for someone who says Ubuntu "has started releasing software a little closer to beta than I am comfortable with." Arch will look like the Ubuntu alphas. But you'll learn how to back out of and work around bad upgrades, and usually things will shake out in a few days. Doesn't sound like what you're looking for though.