Not what you might expect - more of a drama/adventure, less (if any) Sci-Fi I haven't watched all the episodes but to be honest, it isn't what I was expecting from a show that claims to be Sci-Fi and has such good ratings.
Since the action is supposed to happen 500 years in the future, I was expecting high-technology, aliens, cool effects and weapons, weird alien worlds/planets, a bit of horror, violence, etc. Maybe something kind of like a combination between MiB 1, Prometheus, Alien etc.
It's not that. For example, someone gets shot (with bullets!) and they still don't have like a some sort of a pod or something to fix them immediately, it's like 1990s medical technology. Come on, it's 500 years into the future!
There are no aliens, it's mostly humans and the landscape/action is mostly on Earth, with horses and all stuff, guns that are very human like (pistols, shotguns etc.) so sort of western-like. The "space" and "ship going through space" graphics are laughable, even for that time in 2002 when they already had lots of technology to create believable graphics and effects.
Furthermore the action and dialogues are a bit strange at times, can't tell exactly what is wrong with them, they seem a bit off or unnatural. The acting is good overall though, with some interesting appearances, one big surprise being the beautiful and very young at that time, Morena Baccarin.
So to conclude in my opinion the show is somewhat overrated, at least from what I was expecting. Granted I haven't seen all the episodes (I'll try to watch all of them) so take this review with a grain of salt. So if you want to check this series out expect more of a drama and less of a Sci-Fi show, don't get too excited about that.