TomTom is also a poor choice for a mapping partner in our opinion. In our experience, Garmin mapping units have outperformed TomTom. Furthermore, there are no mass transit directions at all on the new Maps. None. At all. Millions of iOS 6 users live in urban city centers, and they're suddenly without the bus and train data that was so easy to find using the Google-assisted Maps in iOS 5. Apple's probably working hard on patching this up, but for now, it's a huge hole. And, on top of that, Google has no standalone Maps app for iOS to cover up Apple's omission. (That's probably on purpose.)
The only major upside? Siri can now control Maps, so you can just say "Route me to 586 Redwood Circle in Santa Cruz" and it'll pull up turn-by-turn directions. Just don't expect it to get you there on a public transit option.
Why is this a negative? Because Siri still isn't smart enough. Yes, she knows more about movies now, and she can make you a reservation down the street at your nearby Chinese eatery, but that's just not enough. There are no API hooks to allow third-party apps to have their vital functions controlled by voice. Why not? Being able to control all apps -- not just opening them, but using them -- via voice would be groundbreaking. Also, Siri's intelligence drops significantly in nations not named U.S.A. Tsk, tsk.
Lack of customizations -
Apple has never been one to really open things up for tweaking, but it's time. iOS 6 is looking a bit dated, and there are still no options for adding third-party keyboards, changing themes or colors, or controlling extras that show up in Notification Center. Why can't we turn Airplane Mode on or turn Bluetooth off from the pulldown menu?
Camera omissions -
Why put a world-class camera into a phone, and then give users no way to truly take advantage? The iPhone 4S and iPhone 5 have great sensors and optics, but Apple failed to turn advanced options on in iOS 6. No way to adjust ISO, shutter speed or aperture? Why not? Creative professionals would be happy to show off the iPhone's capabilities, but iOS 6 limits their abilities.
No live icons -
Why does the weather app still show 73 and sunny? Why doesn't it actively show the weather where you are? Why do the notification number bubbles have to be the same color on each app? Why isn't there a way to tweak that? Plus, there aren't any widgets in iOS 6 -- a missed opportunity.
Contact / NFC -
We can't fault Apple for skipping the mobile payments bandwagon; it's a real mess at the moment, with too many players and no clear roadmap. But, why not add NFC? If anyone could make bump transfers cool, it'd be Apple. Just look at what they did for short-form messaging with iMessage. They clearly have the foresight and marketing and coding skills, but the hardware's not there. It's not so much a knock against Apple for not copying Android and including NFC; it's a disappointment.
iPad omissions -
iOS 6 is still brand new, and Apple has plenty of time to make updates and adjustments. We don't expect the next major iOS push until WWDC 2013 next June, but hopefully we'll get a few wishes granted in point releases between now and then.