What Makes Good Video

I hope someone could enlighten me if possible. Basically, I see so many DVD players on the market, touting how great they are. I see a lot of high-end (mega buck) used DVD players here on A'gon from the likes of CAL, Theta, Faroudja, etc... Yet, most of these players still command high prices on the second hand market despite their lesser technical specs compared to, say, a new Sony. Now, granted, for the most part, Sony does not exhibit the build quality of the aforementioned brands, but it does boast some of the most cutting edge technology.

E.g. CAL's, Theta's, etc... list their video DACs at 10 bit, maybe less, whereas Sony's ES DVD player sports a 14 bit DAC. Yet, Sony's can be had, brand new, for less than the used price of a CAL, not to mention the rest.

Is there more to it? Do DACs vary in quality? Is it possible that a 10 or 12 bit DAC can, with better quality components, outperform a 14 bit DAC?

Just wondering.

Thanks,
H