In addition to everyting said above...when traveling with a companion and you want to ensure you both ugraded, use the RPUs on both of you.
If you think you have the status to clear a UDU, then use the RPU to upgrade your companion first, thus only you have to play roulette and not do it with a +1 after OLCI.
Nothing makes Mrs. B happier than knowing ahead of time she gets to sit in the more comfy chair!