Hi Phil,
I think the Canons still have the edge for astro work. As far as daytime shots go I suppose it is closer but from what I already read the Canon there has the edge for terrestial. If you do sports photography then the Nikon.
Also I have been accumulating some lenses now for Canons.
I plan to do some widefield lens imaging with the Proline 16803 camera, filterwheel, FLI digital focuser and Pentax 67 F4 lenses. I have 45mm F4, 165mm F2.8, 300mm F4 on the way with a special adapter to fit it to the FLI camera being made shortly. The 300mm may only be used for terrestial as I hear it has chromatic aberration for astro. Although it can be used for narrowband (another advantage of narrowband apart from imaging through light pollution is it is not affected by the chromatic aberration of your optical system).
I tried using Canon FD lenses and an STL11 a while back and whilst a few of them turned out OK nothing spectacular. This one was the best:
http://www.pbase.com/gregbradley/image/90484673
But no way would that be good enough to beat Phil Hart at the Malins!! And of course that is the standard I want to be met, hehehehe.
Greg.