High ISO noise CCD's vs CMOS

Ok, I'm in the market for my first DSLR (upgrade from 35 mm SLR and
Nikon 5700).

I've been looking at reviews on the Sony A100, Nikon D80/D200 and Canon
30D.

These are both 1600 ISO (see reviews for more detailed information
about conditions etc).

http://www.steves-digicams.com/2006_...s/IMG_8337.JPG

http://www.steves-digicams.com/2006_...s/DSC_3490.JPG

What a HUGE difference !!!

I see so many people say only if you shoot high ISO is it a concern.
Unless your shooting with lights in a studio can't any one use high ISO
at times?

If you can get 2 (or so) stops lower on every lens and get the same
picture, why not take it? You'll pay a small fortune for 2 stops on a
lens.

Are there other compromises in going higher ISO (even in the low range)
besides noise. Do you lose color accuracy etc.

I really favor Nikon for feel and operation. But this ISO noise has me
leaning towards canon CMOS. I also see numerous comments that Canon IS
is better than Nikon VR. So that to me is worth probably another stop.

So the canon seems to have like a 3 stop advantage over Nikon.

I have no investment in lens (my 35mm was a Pentax and I'd never use
those boat anchor manual focus lens again).