Well Prometheus is a more fast paced movie comparing it to the Original Alien.
The nature of a TV-show is that you got more time for character development. Some shows might even have to much character and not enough story.
But TV-series has a lot of tropes, filler episodes, multiple storylines, flashbacks etc. It just depends on how good they execute them.
And you say you dont hope we end up with 10 hrs of Prometheus, but remember that Prometheus was very split between who liked it and who didnt. So saying 10 hrs of Prometheus is not necessary a bad thing just because it wasnt to your liking