I preordered the 6+ on the 12th and was told that it will be available mid-to-late November

. AT&T is also offering the $200 trade-in value for my iPhone 5, which is a pretty good deal. I checked with Gazelle and they only offered me $165.
I upgraded to iOS 8 last night and am very happy with it so far -- it seems to be quite a bit faster for me. Still going through and learning about all the new features.