This is simply the best phone ive ever had the pleasure of using. Ive had mine for 3 months now and i brings a smile to me face every time i use it.
AS far as apps goes there is everything i need a few interesting games and utilies can be found in the app store. but there are a few site where developers are posting there Beta apps up for people to play with. there is no rooting needed it just a setting to switch on dev mode and allowing apps from non approved sources.

Call quality is what you expect from Nokia- nothing short of flawless. oddly it has a front facing camera with no video calling function? Elop must of killed off that function.

My favorite functions are the NFC and and the command line app. I can just hold my nokia BH-505 head phones to the back of the N9 the phone vibrates and the music has switched from the loud speaker to the head set. Magic.
The Terminal app is cool i dont know many commands but its interesting just to have and 1 up iphone user.
I would tell you to buy one, you should have bought one but unfortunately this phone is better than windows phone and that my friends was its fatal flaw . I'm sure the N9 and the MeeGo Harmattan project killed off by Microsoft. At CES this year Intel/Motorola said that X86 chips where coming to phones. They could have been in the next MeeGo phone (N10?) But that was never to be. and the gadget market is poorer for it.

If you like gadget or Nokia or Open sourceism find a N9 and smile.