I like how you share different approaches and state when each of one could come in handy.
I had this talk a couple of months ago with my girlfriend and now reading an article about it helped me put things into perspective.
Oh and being from Chile myself, I hope you enjoyed being there. Our relationship with money tends to be troublesome. You didn't talk about the cultural part in all this approach to managing a couple's account, but what we see in Chile is that people don't talk about money. It's a taboo, so it makes matters even worse.
Anyway, thanks for sharing the alternatives very clearly. It makes it much easier after reading your article!