A possible disadvantage is that your wife may "disappear" with the mutual account. It happened to me (Mr. Honu & I have different last names). For two years I didn't even have an HHonors card with my name on it (I finally received one a few months ago, after asking Yasmine to help), and all the certificates were in Mr. Honu's name. It was a pain, but it seems to work properly now.