I have been a long time Nokia user. Last phones N97 mini (more than 3 years) and E65 before that. Finally, I have upgraded/switched to Nokia Lumia 820.
Things I like 1. The phone is very fast. Screens and pages open extremely quickly. 2. The screen is big and bright, easy to see. 3. Reasonable prices for a phone (which can be dropped and broken). 4. Easy to make calls and send SMS. I use it mainly as a phone. 5. Excellent integration with Hotmail/Outlook and Messenger (the later in process of being killed). 6. Wireless charging is excellent (charger sold separately and I have one which is not Nokia branded). 7. Uses the same micro-sd from my old phone (with my music instantly transferred from the old phone). 8. Replaceable battery for the day when it does not hold enough charge for a day (seems to last for 3 days with very light use for now). 9. Touch screen is excellent and can be used with gloves and big fingers. 10. The customisable `Live tiles' and the ability to show large contacts on the main screen. 11. Maps can work offline (my carrier has prohibitively expensive data roaming charges/rates). 12. Most of my old applications are available for the new phone. Plenty of new applications and games. 13. Pictures and videos are very good for a phone. 14. `Find/ring/erase my phone' features. 15. `Free music' and offline music mixes from Nokia music. 16. Uses micro-usb charger and data cable (same as my old phones). 17. SkyDrive integration for pictures/videos and documents. 18. OneNote. 19. Easy to close applications which have been used and no longer needed. 20. Headphone jack is on the top. 21. Rigid back cover (requires some strength and practice to take out). 22. `Kids corner'
Missing from N97 mini 1. Remote SIM for the Bluetooth which allowed my car to load the address book and show on the car's screen the name of the caller (only the number is displayed with Lumia 820) 2. The option which allowed the phone to pronounce the called name so you know who is calling even when you cannot see the phone screen (in the pocket and dirty hand, in the other room). 3. The pulse light which tells you that nothing needs attention when reunited with the phone (after a meeting for example). 4. The ease with which a song can be set as a ring tone. I do not understand why in 2013 I have to connect the phone to a PC and then copy (and maybe convert before) the song to the phone to be able to make it a ringtone (if want to use more than 20 sec of the song). 5. Stereo sound from the build in speakers
Things which Nokia/Microsoft needs to improve on 1. DLNA player or application. 2. Backup/restore (especially the later) is very basic and does not meet my expectations (set by N97 and rival phones). 3. Vibration can be stronger. 4. Ring volume when on max can be stronger. 5. Skype integration with `Me'. 6. Ability to re-assign the third (search with Bing) button functionality (may be search in contacts only as a default). 7. Better multitasking for background applications. 8. Mute/un-mute button.
On the whole it is an excellent phone for the next few years.