In my experience the sony ones have been good in low light, however their low light capability was cut back a bit after the big nekkid video scandal. It seems that their sensors were a bit too sensitive to IR so you could see vague body shapes and "hot spots" through clothing. The filters they put in the cameras to "fix" this reduced their low/no light performance though, since the IR sensitivity was reduced.
Some baby cameras and webcams have either no IR filter, or an IR filter that can be easily removed. That makes them a lot more sensitive to IR so you can see the kids sleeping better when the lights are off, at the expense of sometimes being able to see someone's underwear seams or outline of their bra when the camera is in night mode. It's only a big deal to immature troublemakers...
Still, as much as I hate sony as a company, their camcorders are pretty good. I think I have a hard-drive storage samsung or jvc camcorder right now because the price was right, but it's not HD.
