I hear rumors the Canon 5D/7D are good in Low light but are they better than video cameras of similar size?

Which is best in Low light of the most current HD cameras listed

Canon 5D / 7D.
Canon HFS10
JVC HM100

You'll need a fast lens (wide aperture) to get the most out of the DSLRs in low light, but there's really no comparison to the small HD video cameras you mention (with their comparatively tiny sensors).

I had the HSF10, sold it when the 7D came out. In terms of low light and DOF control they are a world apart.

The 5D could potentially gather in 5-10 times the light of a HFS10. It's not even worth discussing the gap is so big.