although canon is excellent in bright light shots, and panasonic would offer 3CCD within the same price range, but when we enter the low light world, sony is the only choice (don't expect too much even from sony b/c low light is a nightmare to any DVs)

About still image, never expect the same result from a DV as a dedicated DC.

About format, I'd suggest built-in harddrive.

If the size matters, choose those using memory cards (SD, memory stick etc) as recording media. Ultracompact size would draw you a lot of compliments, but the recording time is limited...