One of my settings involves a transitional period in space travel. There's no real FTL yet and one nation had made the breakthrough in gravity panels, but it's a slow adoption process. What this means is that they have this vast trade fleet of thrust and rotation gravity ships and a handful of next generation grav plate ships. It's a real big mish-mash of old junkers and cutting edge sleek ships with permanent gravity. Though being a people so used to living in space for so long, it's almost perverse to return to gravity since they got so good at living in micro-gravity.