Not going to mention some obvious advantages based on specifications like HD movie , frame rate, face detection in Live view etc,
Only wish to express some feeling after using as a experienced Nikon User.
The user interface of this Camera is very user friendly
Better than D300
Excellent user interface, easy to change camera settings on the info screen by little joystick and Dial(Very useful)
Live view operation as convenient as prosumer camera
Resolution of 18Megapixel is really much better than 12M of D300, good high iso performance at such small pixel
In backlite situation, exposure for the subject is excellent without fill in speedlight when use evaluative metering
IS performance of 15-85 is better than VR of 18-200 in Nikon. and 15-85 is a very sharp lens
Photoreview is more convenient, for example you can sort by date while Nikon cannot
About the same as D300
Overall excellent metering
Good auto white balance in artificial light which was very weak in previous model(Big improvement)
Auto focus in terms of speed and accuracy is about the same as D300 when using single point in the centre
Auto Lighting optimizer performs very well in complicated Lighting environment, which is called ADR in Nikon
Focus tracking for moving object is still inferior than D300
D300 focusing system is still better but Canon is very very close
Although flash exposure has improved a lot which was poor for the 40D but Nikon is still better in this aspect
I am a Nikon users for many years, not mentioning film cameras. Have used almost all generations of Nikon DSLR from D70, D200, D300 to D700. Now sitll have D700, D60 body and many Nikon lens.Have used D300 for almost 2 years. Have own Canon 40D before but sold it after half years, since I think 40D was inferior to Nikon in every aspect except skin tone in Potrait photography. Always think that there are good Canon lens but no good Canon cameras.
This 7D is really a big suprise for me, I like this camera very very much and from now on I will bring it with the 15-85 lens for vacation to replace my D300 with 18-200 I used before.
This does not imply I switch from Nikon to Canon , I still use D700 with 24-70 f2.8 lens for serious photography but at least this is the first time I think that Canon is also worth keeping. I will buy more Canon lens and pay more attention to Canon new models in the future and WILL NOT change my member's login to CanonHo!