Originally Posted by corporate-wage-slave

I can also confirm that GUF can be combined with flights with (e.g.) AA sectors on it. You get the benefit of having one ticket for protection purposes (not so relevant with AA / US). The upgrade only applies to the BA sectors, as Chris1979 points out. It may still be cheaper / easier / more flexible to have separate bookings, but at least the option is there. I had this experience earlier this week, on a pure redemption booking with GUF1 and another FTer PM'd me about it a few weeks ago, I think with a GUF2.