A great design is important for a great user experience, that's where Apple is far ahead of the competition
I absolutely love the design of the iPhone 6! The rounded edges feels so good, and it's so easy to handle with one hand. So light and thin.
Beautiful design and a perfected device is very important for the experience. The user experience. Everything from the hardware to the UI and Apps needs to be beautifully designed.
The Apple Watch will probably not be perfected yet, the first version usually never is, but it will be near. Apple knows what they are doing. Apple is famous for the great user experience so I trust them to give us the best user experience on such a small device. It's not android manufacturers we are talking about here, that let the users be guinea pigs (crash test dummies) for their own experiments only to be first, and then when apple has thought out how to do it right, copy it for their own products.
Of course Apple didn't invent the watch, not even the smartwatch, but they have “re-engineered” it to finally be useful.
And because I think the Apple Watch will be a great companion device to the iPhone, I'm thinking of switching to the Plus version of the iPhone next time. So I will probably buy the iPhone 6S Plus. One of the reasons why I would like to have the bigger iPhone now is that some things has changed for me that makes it harder to use my iPad Air 2 as much as I would like to. So I have to use a more pocketable device like the iPhone more. And having a larger screen than the normal iPhone 6 would be ideal for me now. And I don't think there is a point in switching already with just 5-6 months left until next iPhone is released. So I will use my iPhone 6 more now while I'm waiting for the next iPhone 6 Plus to be released. But the iPad Air 2 will of course still be my main device, my computer. But the iPhone will be a compliment to it more now in my post-PC world.
To me the user experience is much more important than specs, but with Apple devices you get both. All thanks to that Apple controls both the hardware and software. Openness and free is not always better you know.