Thanks for all the responses!

As for whether Ruby is worth it, I find I can make it without that much difficulty, and the extra points are quite nice, plus it makes a real difference for getting through lines faster at the airport (particularly security when going on AA flights). Cathay also gave me exit row for free, which was nice when crossing the pacific!

Definitely not in the league of Emerald (to have lounge access would be rather nice...), but IMO still worth it as long as I don't have to go too far out of my way.