Going to purchase a new widescreen HD "flash" camcorder and have narrowed down to these two models. Any opinions? The only real difference I can see is that the sensor on the HF20 is smaller - 1/4" vs. about 1/2". Obviosly the HFS10 has more pixels, but I'm wondering how much of this will I really notice when taping band concerts, vacation videos, etc... Is the HD capability of the HF20 enough to account for a $400 difference?