I'm a Nokia convert and so far I have no regrets. However, you have to be prepared to spend sometime to get used to it.
As mentioned by someone else before, the keypad requires a little more force to push, but some sau that its a good thing as possibility of keying in the wrong number or alphabet is minimized.
I had to get used to the layout as well, always press the RIGHT softkey and end up getting a warning message if I want to delete the contact or message instead of going Back. Still need to get used to the Back Key!

Another thing I just realised - I was typing an SMS and wanted to insert someone's phone number and I realised I can't do that unlike Nokia where you can access the phone book and insert a phone number.
So what I did was to save the SMS as drafts, exit the Messaging, enter Phone Book and copied the phone number, go back into the Messaging menu, edit the saved message and paste the phone number in there.
Quite a lot of steps, is there a shortcut or am I missing something there?

I guess the only way now is that if I know I need to send someone's contact number, I can copy it before I start composing the SMS. But that is still several extra steps, unlike Nokia's where you can enter the contact number while typing the SMS itself.
3 weeks of owning the phone and I'm still learning something new! Its like a puzzle!
Thx for the input, very nicely said:D.
Well, I might consider getting a K800i around CNY i guess. What is the rough and average price for a K800i now? I would like to know the figure so i could get one for a reasonable price.