We prefer Sci-Fi. I enjoy the quiet atmosphere, the darkness (gives a bit of a reprieve from the harsh daytime sunshine), and the movie clips are fun. And sometimes I just want a really good burger lol, and I think the one at Sci-Fi fits the bill. Plus, it's pretty close to Star Tours, which we like to ride at least 4 times while we're at DHS. We're really not fans of teasing, so 50s PT just isn't our scene.
When I ate there the first time, I was with my mom & stepdad (party of 3, like you), and we didn't have an ADR, and they sat us at one of the "flying saucer" tables in the back. At first I was bummed that we didn't get a car, but we had more leg room, and there are little speaker boxes on the "fence" walls, so you can hear the movies just fine.