Well I have a 350d, and TBH when I compared the Nikon and the Cannon I felt more comfortable using the Cannon Layout. Alot of people say the Nikon is easier to handle, but that just shows its down to personal taste
Biggest downside of Nikons I found is the limited number of aftermarket lenses, from the likes of Sigma, Tamron stc.
The overall quality of both is very good, and it really is down to howe much you have to spend, and which ones feels right in your hands.
rubbish all lens makers that make lenses for cannon also make them for the nikon, every model they make for the cannon make the nikon equiv!!!
but on top of that nikon also has prob the best lens maker in the world producing lenses for them (karl zeiss) so hush your mouth with your cannon fan boy rubbish lol...
i use nikon day in day out, personal dslr is a nikon d2x and i use anything from my camera to things like hassleblad digi medium formats... also use cannons however thing i dont like about the baseline cannons is the build quality they feel plasticy and fragile, i have dropped my old d70 down stairs, and dropped my d2x and neither broke, dropped a 350 on to grass and its case split in half lol, (i dont make a habit of dropping cameras) another thing i prefer with nikons is the fact you have a wheel either side of the shutter release, front is aperture and rear is shutter speed adjustment, on most cannons you have one which controlls both and you have to piss around pushing a button to adjust it, on nikons i can adjust on the fly using the viewfinder lightmeter plus one other pet hate is cannon using dumb ass abrieviations for shutter priority etc, nikon is simple, s,a,m,p (shutter priority, aperture priority, manual, pre program or auto mode) none of this tv, av bullshit lol