1. Beautifully crafted (yes, yes it is)
Meh, I prefer the design of the htc sitting next ot my iPhone. The metal and rubber back is a lot more practical as well.
2. Great UI design
Outdated and looking it. I much prefer Windows Phone 7's live tiles and, to a lesser extent, the widgets on Androids home screens. More information at a glance, when you need it. iOS is showing its age.
WP7 has the chance to be a great platform, but it stil has some teething problems, but it is still better than iOS IMHO.
3. Beautiful hi-res screen
So have my htc phones...
4. Decent camera with good optics, that make good photos and video (lookin' at you HTC)
The camera on the Sensation is ok. But that said, regardless of whether I carry the iPhone or the Sensation, I still carry an Ixsus or an EOS for taking pictures...
5. Pocket-size (none of your 5in monstrosities please, if I wanted a tablet I'd have asked for it)
The Sensation is fine, fits into my shirt pocket without problems, feels good in the hand.
6. Top-notch build quality
Hahahahaaha! We've had 12 replacement iBones for 3 users in the past 12 months! 2 iP4s were delivered with defective batteries (only usable when plugged into the power adapter), Another 2 had defective WI-Fi and BT (30cm BT range, 2M Wi-Fi). We've also had defective speaker shielding problems, batteries dying after 3 - 6 months, graphics chip problems (white display).
Couple that with the repair policy here (Germany), where they take the iPhone away and return it 2 weeks later (in one case, the same phone was sent away for a total of 6 weeks in a 7 week period, before they finally gave up and replaced it!). htc on the other hand deliver a replacement handset when they collect the old one.
7. Decent battery life (*at least* comparable to other phones with similar specs, and if you tell me your HTC, Samsung or Droid or whatever gets 6x the battery life I'll just laugh at you)
With a Mofie, maybe... The battery on my iPhone lasts about as long as the Sensation or Mozart with similar use. The advantage of the htcs, I can carry around a spare battery in my pocket, in case it runs out during a trip.
8. High-quality apps, guaranteed to work (and work well) on my device
Same for WP7 and Android. I have the same apps (with the exception of the lack of an Audible app on WP7) on all my phones and they all work - although since iOS 4.3, iTunes has a tendancy to corrupt my Audible collection on a regular basis, one of the reasons I got the Sensation.
9. Good customer service (YMMV but I've had great service so far)
See 6 above, Apple's support here is dreadful, unless you want to take out an extra 50€ "protection" plan, then the service rivals htc's standard service.
10. Great, truly great, media sharing capabilities, useable by The Average Joe(TM)
I have wireless sync between my desktop and my Sensation of podcasts (I don't have any music on any of my phones). I will give Apple a plus point here, it does (sometimes) remember where you stopped listening to a podcast on the iMac and carries on where it left off on the iPhone, but it has become less reliable with each update.
11. Great accessory ecosystem
I have desktop docking stations for the Sensation and the iPhone... But the Sensation's docking station also has a tray for recharging a 2nd battery. I also have a nice Bugatti leather case for the Sensation, my Hi-Fi has USB and Audio in for playing back media from any of the phones...
I bought my iPhone 3GS, because it was the best at the time. With each new release it has become slower and less reliable, even the hand-me-down iPhone 4 (the owner switched to a Samsung Galaxy SII) failed to impress and the Mozart I got through work was much better. For my private contract, I now use the Sensation, the iPhones sit in a corner.
Apple have lost their lead and the 4S refresh seems very much "me too" in terms of hardware features, as opposed to being a clear market leader. The iPhone 4S isn't bad, but the rest of the market has caught up, and in many places, it has overtaken the iPhone.