I left this unfinished until I had tested both of the new iPhones, so it goes from the initial event response to some recent thoughts.
iPhone 6
iPhone 6 and iPhone 6 Plus were pretty much as expected. I think they'll both sell very well, as already demonstrated by a record setting launch weekend for Apple, and still limited availability. I was a little surprised by the 6 Plus' resolution scaling but that kind of thing might allow greater flexibility in future sizes with less rushed developer changes. Although given the Twitter complaints about scaled Apps, maybe not.
I was pleased by the rounded edges. Both devices seem more comfortable for that point of contact. The iPhone 6 Plus with Zoomed interface enabled looks great for older users (as long as they can grip it) and those with vision issues.
Increasing the size of the standard iPhone with the Plus has made room for a possible nano at a later date for buyers less happy about the change. Current choices are ‘go big or go old’.
@mantia: I think Apple made a huge mistake this year by not releasing any smaller phones.
I think it's a very clever move by Apple. Going big makes some of the previous complainers happy this year. A new or major upgrade to a smaller model next year gives the New factor the press and public want in an ‘S’ year of the usual cycle. A potential 6S and 6S Plus (sounds like an Android phone) being less significant improvements in the Year of the Apple Watch. It's far too early for predictions like this.
Websites of the UK phone networks handled the launch day badly as usual, except Vodafone who seemed to cope.
My first close up sighting of an iPhone 6 Plus was in a coffee shop and my immediate response was ‘Wow, that's ****ing huge!’. After finally using it in an Apple Store, it is definitely too big for me and I have fairly large hands. It crosses over into the small tablet category with other phablets. If you get a 6 Plus you would have much less use for the current iPads and especially the iPad mini. The iPhone 6 also seemed quite large but more manageable. It will take some time to get used to it. My one handed usage will have to decrease a lot but I was trying to do that anyway for the sake of my thumbs.
With my previous iPhone increasingly crying for retirement, I was ready to walk out with iPhone 6 but UK Apple Stores have limited stock and none of the (probably) most popular 64GB Space Grey/Black. As an App developer, getting experience on these new sizes will be very important as I start to consider work after my PhD.
Apple Pay
Apple Pay, NFC based... interesting, waiting for the magic words...
US Only
I wonder if it'll beat iTunes Radio to UK availability. I also wonder whether it would be the same given the much stricter EU requirements on card transactions. Contact-less NFC payments here are limited to a set relatively small limit but that's plain touch and go without the additional protection of Touch ID (fingerprint).
US release so far seems very well received but expansion may be hampered by some big retailers only supporting their own rival mobile payments solution. CurrentC by MCX (a consortium of retailers) is QR code based payment App not yet widely available. It seems to be much more in the interest of retailers than customers, designed for gathering data about customers and purchasing habits.
Apple WATCH
On a Mac it's Shift + Option/Alt + K (updated: on non-Apple devices you probably cannot even see the symbol).
My initial response was intrigue more than real want. They did not sell the reason why we should have one as well as other announcements. It just seemed to be flashes of features which all seemed to be given quite equal weighting. Ben Thompson's Stratechery articles provide a better discussion of this than I could possibly write here.
The other memorable thought was being concerned about the longevity. A good watch normally lasts a long time and some of the integration aspects may no longer work as well a few iPhones down the line. Combine this with the fact that the initial yearly releases could be significant improvements, especially in terms of battery, the lifespan of the first may not be that long. Others mentioing this speculate that Apple might provide good trade-in value, especially for those involving expensive metals, or move towards an upgradeable core.