It's not just the pilot - ScyFy has put the first four episodes out on t'web already.
It were alright, but I thought the made-up space language stuff was an embarrassing throwback, as was the pointless zero-gravity sex scene and tacky tracking shots. Also, it suffers from the usual problems of much of SyFy's output in that its fictional world doesn't make much sense, though for some reason what stuck with me was the usual "oppressed underclass" guff - how many engineering degrees and years of training would you need before getting to the point where you could swing a pickaxe in space, yet we're expected to take it as read that none of these (possibly literal) rocket scientists would join a union? This "Earth is the oppressor of all the colonies" stuff is pretty unworkable if you play it too serious, but stuff like the more campy Killjoys and Dark Matter got away with it by playing up to the idea of the upper classes being an evil empire of some sort, whereas Expanse just seems to want you to take it at its word that Earth controls everything because Reasons, even though it seems happy to overexplain a lot of other stuff considerably less essential to the coherence of the fiction.
Still, it's a space opera coming out just as space opera has become huge again, which is a no-brainer, shirley?