Make of this what you will. I’ve interspersed updates into everything that follows.

When I ran my older apps, everything ran at 320×568 on the new devices. To get the following numbers, I created entirely new projects. (Saniul Ahmed tweeted me that you need to provide current launch images to get the new dimensions.) Lesson: Update your launch images or create new projects to take full advantage of the new dimensions.

From the docs: “The iPhone 6 Plus uses a new Retina HD display with a screen scale of 3.0. To provide the best possible experience on these devices, include new artwork designed for this screen scale. In Xcode 6, asset catalogs can include images at 1x, 2x, and 3x sizes; simply add the new image assets and iOS will choose the correct assets when running on an iPhone 6 Plus. The image loading behavior in iOS also recognizes an @3x suffix.” So the 6 Plus is 3x. Right. (Even though it’s reporting oddly  in the below info dump.)

Compare and contrast with the marketing text: “The size of the new, higher-resolution Retina HD displays on iPhone 6 and iPhone 6 Plus may be the first thing you notice.” (The same  HD mention is here as well.) But the 6 non-plus is reporting correctly for @2x ,not @3x, so I suspect the marketing text is wrong. (Thanks akempgen)

Lesson: The 6 plus uses a 3x scale. The 6 does not. Retina HD seems to mean something different between marketing text (high density) and developer docs (3x resolution).

More explanation about iPhone 6 screens from the guys at PaintCode. Read about it here. Lesson: This new stuff is strange.

With no further ado, here are my original tests.

Testing iPhone 6 plus
iPhone Simulator
iPhone OS
8.0
iPhone Simulator
<UIView: 0x7f854596f7a0; frame = (0 0; 414 736); autoresize = W+H; layer = <CALayer: 0x7f854596bd50>>
<UIWindow: 0x7f854596e1e0; frame = (0 0; 414 736); gestureRecognizers = <NSArray: 0x7f854596edd0>; layer = <UIWindowLayer: 0x7f854596c0d0>>

Testing iPhone 6
iPhone Simulator
iPhone OS
8.0
iPhone Simulator
<UIView: 0x7ffb11415b80; frame = (0 0; 375 667); autoresize = W+H; layer = <CALayer: 0x7ffb11402be0>>
<UIWindow: 0x7ffb14113000; frame = (0 0; 375 667); gestureRecognizers = <NSArray: 0x7ffb14113a20>; layer = <UIWindowLayer: 0x7ffb1410f410>>

Testing iPhone 5s
iPhone Simulator
iPhone OS
8.0
iPhone Simulator
<UIView: 0x7fcb21d13d90; frame = (0 0; 320 568); autoresize = W+H; layer = <CALayer: 0x7fcb21d13090>>
<UIWindow: 0x7fcb21d10e70; frame = (0 0; 320 568); gestureRecognizers = <NSArray: 0x7fcb21d11770>; layer = <UIWindowLayer: 0x7fcb21d0d140>>

Testing iPhone 5
iPhone Simulator
iPhone OS
8.0
iPhone Simulator
<UIView: 0x7a0d6a50; frame = (0 0; 320 568); autoresize = W+H; layer = <CALayer: 0x7a0d6310>>
<UIWindow: 0x7a17a5c0; frame = (0 0; 320 568); gestureRecognizers = <NSArray: 0x7a17ac00>; layer = <UIWindowLayer: 0x7a17a550>>

Testing iPhone 4s
iPhone Simulator
iPhone OS
8.0
iPhone Simulator
<UIView: 0x7ae9a000; frame = (0 0; 320 480); autoresize = W+H; layer = <CALayer: 0x7ae9c730>>
<UIWindow: 0x7ae9c600; frame = (0 0; 320 480); gestureRecognizers = <NSArray: 0x7ae9cb20>; layer = <UIWindowLayer: 0x7ae9c210>>

Anyway, this was what I tested out: