i have used Canon 350D, 40D, 5D, 7D Nikon D50, D90. D300, D700.
The following is only my own option.
For Focus system(on D700 > D300 > 7D > 5D), Nikon is still better.
Noise control (D700 > 7D > 5D > D300) 7D is actual quiet good.
Sharpness is (D700 > D300 > 7D)
Color (D700 > 7D > 5D > D300)
Body (D700 > 7D = D300 > 5D)
LCD(7D > D300 = D700 > 5D)
view finder(D700 > 5D > 7D > D300)
For photo only, I will 100% perfer D700, but i need video, so I turned to use 7D.
For a APS camera, It is one of the best already, especially in noise control. But for only focus system, i still perfer nikon..