Here in Florida, I would have done the exact opposite. Chain and cassette are wear parts that have to be replaced, and if you ride where there is a lot of sand or sandy dirt, the wear on these parts is exponential. Also, the smoothness and accuracy of the shifting is controlled by the shifter mechanism more-so than any of the other components. I've actually run both the XX1 and GX derailleur on my GX 11 setup and there is literally no difference in shifting performance. It's a lot of money to fork out for a few grams savings.
Regardless, I too will be moving to the Eagle setup this season. Seems this new video editing gig I got gives me a lot more mobility and freedom, so there are going to be many more trips to GA, NC, and TN in my future. I climbed Live Wire 1 and 2 up the back of Raccoon Mountain and with a 32 in front, I could have used the 50 rear. Normally, my bike is setup with a 34 front since it's pretty flat here. With a 1x12, I could keep the 34 or possibly even run a 36 in peak season when I'm riding heavily and my legs are in shape to push a gear that tall.
Have fun with the Eagle.... I'll have to envy yours until mid October when I have some extra cash to upgrade myself.