What a phone!
Ok, only had it for a day, so it remains to be seen if there are many bugs, although its not locked up or done anything odd yet and I've been messing around with it a fair bit.
Camera is superb, menu design and speed is brilliant (a real joy to use), magic gate memory card option is great, bundled with everything you need (headphones, usb cable, memory stick duo adaptor, etc), MP3 player is superb, as is radio, phonebook as good as it always is with SE phones + a few enhancements. To name but a few things I already like about it.
A big step up from the K700i imo.