I switched the boat 2 recently just because Jessops are not stocking Nikon D200 for some reason, so I bought Canon 30D.
My initial thought of Canon 30D was RUBBISH handling! Everything feels so Electronic like a toy compared to my borked D70 which felt very good in the hands and it felt like Film Camera. The button layout and option is below par.
Also the shutter sounded weird (a bit clunky).
The plus point with Canon 30D is, easy to scroll throught pictures. Less noise (not very important to me), The same equivalent lens seem to be much cheaper then Nikon and has wider choice.
I went with Canon because of my budget, the Pro grade lenses are so much cheaper. 