Honestly, I love the David Character, almost or just as much as Ash. Bishop is great too but not as intriguing as those 2. David's character is just awesome, would love to see the sequel made but with a bit more focus and story towards the Alien also. I didn't except though he'd take over the whole story. I liked the way he was used in Prometheus, that David was much more liked I'd think. Now he's become a bit annoying.
It'd be freaky if David and the cargo were captured by real Space Jockeys and his anatomy and experiments were blended together to create a bio-mechanical Alien. I'd imagine trying to create that entire scene would be messy and complicated though.....