You make valid points but the reason there are many Apple fanbois here is because it is a forum dedicated to Apple products.Watch out! Plenty of fanbois around here...
Its a shame you didn't get on with the iPhone, but public opinion (as gleaned by me) seems to indicate that you hold a minority opinion. That's not to say its wrong, of course. You're completely entitled to your views. But I think the points you make, although valid, are probably concessions most people are willing to make at this stage for the other benefits the iPhone offers.
Personally, I loved my K800i. The best phone I had. Before my iPhone. But in my opinion my iPhone is leagues ahead of the K800i.
I tried to get the K800i to do music. I tried to get it to do web browsing. I tried to get the K800i to do GPS navigation with an external bluetooth GPS adapter.
Then I gave up and just ended up using it as a phone. I still wanted a music player and a navigation device, however.
Then realised the iPhone could do it all, and I was quite happy to leave GPS up to TomTom.
My only other gripe with the iPhone is lack of 3G. But I'm almost never away from WiFi (which is super-fast on MobileSafari), and I don't think I'm ever going to need fast data access THAT much when I'm on the road. I think I'll settle for O2's iPhone data plan and GPRS transfer speeds for the odd occasion when I'd like to pull down weather or traffic information.
You mention A2DP stereo over bluetooth and voice dialing - and, while this would be nice, I can understand that no one can produce a first generation device that can do it all, and these are all things that could be added with a firmware upgrade in the future. (plus, I never got voice dialing to work usefully on my K800i).
You also mentioned iTunes syncing. I'm really not sure what your problem is here. Its been seamless for me. In fact, the whole experience of the iPhone has been seamless. I get the merest few seconds of hang in iTunes when I connect my iPhone, but it unhangs quickly and performs the task without fault. I can only guess that if you're having problems, its either related to iTunes and your media, or something else on your computer.
I'm one happy iPhone customer, and would never go back.