I think the extra half bath is essential. It never fails, when it's 'in use', it's also needed by the other person.
It also came in very handy when I took my two 13 yr. old great nieces on their first motorhome trip this past summer. Girls like to be in front of the mirror so the half bath was theirs. Oddly, they WANTED to use the rv park facility showers which they didn't have to. That worked well since there were four of us.
Safe travels,
MM.