If both are mpeg-4, then the differentiations are:
- CCD 7MP vs 5MP
- Lens casio-home-made vs German Schneider
But in 640x480 mode, 7MP may not have any advantages at all.
So it turns to the lens, and traditional wisdom says German lens are usually higher-resolution and sharper.
Casio is a new comer to the lens industry (previously it OEM from Pentax or Canon).