Went to a T-Mobile store at about 6 a.m. and lined up. I was 8th in line, and there were probably twenty in total when 8 a.m. rolled around. They came out and told us that pretty much no stores in the Pacific Northwest got the 6 Plus in and that we could order it, but it wouldn't ship for 6 to 8 weeks. I had already given up on the 6, so I happily went with a 6 in Silver and 128GB (I wanted 64, but for Silver, they had only 10 models of the 128GB and no other configurations).
Just setting things up, but I'm really pleased with this so far. Coming from an Xperia Z1s, this thing feels light and tiny, but the screen size is quite nice. Beautiful looking screen, too. I actually like the aesthetic of the device much more in person than from the pictures I've seen online.
My opinion may change when I get to play with a Plus, but for now, I think this might have been the right decision.