Specs for the N96, N78, 6220 Classic and 6210 Navigator

I don't claim that these are the specs to their fullest, however they are the features that seemed more important at first glance. There may be things not included in this list that are there (e.g. Bluetooth), they're probably not listed because they should be expected in any smartphone in 2008. My personal opinions to follow later today.

N96

-2.8 inch, 240 x 320 screen (this is really a disappointment)
-16GB internal memory + microSD slot
-faster USB transfer, apparently (it was about time to go beyond the 1MB/s marker, especially considering the 16GB of built-in memory)
-3.5 mm audio jack
-media keys
-location tagging of photos
-103 x 55 x1 8 mm (actually max.20mm)
-125g
-950 mAh battery BL-5F (another major disappointment)
-5MP Carl Zeiss AF camera (probably the exact same module as on the N95) with dual led flash (although a lot of people consider this to be another disappointing factor, I personally disagree as I understand that a xenon flash can not be used for video recording - and given this device's being marketed with a strong focus on video, it only seems natural to be able to shoot videos at night as well), video recording up to 640 x 480 at 30 fps
-aGPS
-micro USB
-Flash Lite 3 in browser
-S60 3rd FP2
-HSDPA only on 900 and 2100MHz
-WiFi, naturally
-and many more.

N78

-WiFi
-3.2 MP Carl Zeiss AF camera, video capture up to 640 x 480 at 15 fps
-up to 24 h (!) music playback time
-integrated FM transmitter
-113 x 49 x 15.1 mm
-102g
-aGPS
-2.4 inch, 240x320 display
-Navi Wheel
-1200 mAh battery
-micro USB
-and many more.

6220 Classic

-2.2 inch 240 x 320 display
-aGPS
-HSDPA, no WiFi
-5 MP Carl Zeiss AF camera with xenon flash, video capture up to 640 x 480 at 30 fps
-108 x 47 x 15 mm
-90 g
-micro USB connector
-and many more.

6210 Navigator

-accelerometer
-2.4 inch QVGA (240 x 320) display
-aGPS
-navigation usable without sim card
-103 x 49 x 15 mm
-117 g
-3.2 MP camera with led flash, video recording up to 640 x 480 (VGA) at 15 fps
-2.5 mm audio connector
-950 mAh BL-5F battery (disappointing again)
-and others.

A quick thought: the devices that presumably need the most power (the N96 because it's such an all-in-one device and the 6210, obviously, to be trustworthy for navigation purposes) have the same, low-life battery. Not a good idea in my opinion.