Just play SD with some small fighters. And compare a similar game by using AT small fighters. Then discuss what you preferred to play. The BT universe has the bad 'Clans' and the SD one has the jeez, arrgh, sheeet the Brood! Otherwise the 'fragmented' house system is common to both.
I prefer playing SD, but the setting is uninspiring at best, so that's the driving force to do a conversion. There's also the bling factor. Sorry, but in general, SD ships are butt-ugly, no wonder why it doesn't attract many new players.