I was seriously surprised at how well the A1 (single-CMOS HDV) performed. Here's a video I created last summer, shot entirely on an A1:
You'll always have to do color correction, same as you would on a 3-chip. In good lighting, the single CMOS was close enough to the 3-chip CCD Z1 to combine footage, with a little tweaking.
The biggest difference is not the color or midtones; it's the highlights and dynamic range. A good 3-chip CCD has a little bit better dynamic range, and you're less likely to blow out colors (particularly skin tones) if it's a little overexposed. But, the CMOS chip won't smear with bright lights, like the CCD does. But the CMOS has occasional rolling shutter artifacts, depending on what you're shooting. I don't think either is "best;" it depends on your price range, what you're shooting, and what you're willing to live with.
On that video, I did do a lot of work to try to fix and enhance color -- sometimes replacing a blown-out sky with blue. I was also trying to make the camp look a little more colorful and appealing than it actually is... There was seriously no way to fix the pond, though. No way in the world to make that pond look good...
If a 1-chip CMOS is what fits your budget, go for it. Light well, and you'll be fine.
