I like to have a better control of the 3.5mm output, that's why I use a
JL-Audio CL-RLC preamp/vol control from my tablet-pc into my OEM headunit. Works good enough for me, but maybe you have already a better setup. But unless you want 5.1/7.1 audio, I wouldn't worry about going all digital, but I think I'm in the minority here.
It seems to be a better than average screen, but there's no enclosure for it, so I'm not too excited at this point. It's a bare screen, no enclosure or headrest kit. That's the beauty of the Mo-co-so screen, great price, brilliant enough, and the headrest kit. There's a video comparing it to the Samsung one somewhere, I think it's on mp3car.com front page.
I would also think about using two screens mounted on the roof, but instead of in the center (which would block the rearview mirror), putting them on top of each headrest.