I have read several threads, searched topics and threads but I still don't quite understand how the whole upgrade thing works. Or when to use an RPU or GPU instead of hoping to get the CPU. What happens if I do an upgrade using a GPU/RPU but could possibly be CPUd? Do they CPU first, or does the GPU/RPU trump the CPU? I am a 1K, flying PIT - PHX. I have already been CPUd on one leg of the trip out. The trip back is showing there is 9 seats available for upgrading using RPU/GPU or miles. How does one decide what is the best chance for upgrading? I am not really interested in using miles to upgrade since my RPUs/GPUs expire the end of Nov. Hope this made sense. TIA for any advice.