I take all my flats against an LCD screen with very short exposures so it never eats into my imaging time. Of course I can do this because I have a small scope (I also use a DSLR rather than a small-diagonal CCD chip so flats are pretty essential for me).
Dark and bias images seem to make very little difference to my images overall, but flats I consider to be pretty critical.
Sorry that my sample size of one is also an outlier for your thesis of small-area CCDs.
Cheers,
Cam