i always felt that one of the awesome things about the show was how ftl was considered antiquated technology and that, besides the military, only the older and the nicer ships had them; while the newer and much more common average ships didn't
something about a society that is both capable of traveling through the stars and has collectively forgotten where it had originated from in the galaxy; but widely considers both unimportant is super fascinating to me.
checkout out the treball channel on youtube; they did an entire one hour episode on the differences. tldr: they're all extremely minor and there's lots of them.