I think both these movies required a bigger budget to play around with.
End of the day, you have two franchies in one film, it would have made sense for 20th centuary Fox to give them the money to make them something special.
Even though I enjoyed both movies, I know they could have been sooo much more. All I'll hope for is one day we will see that.
Listening to the commentary on AVP R, the brothers constantly repeat e.g. "Urmm we wanted to do this, but couldnt cause of budget" or "urmmm we wanted this to happen but we didnt have the money"....
The brothers did their best with very little...
Like I said though, enjoyed them both, they had the Alien and Predator for christ sake! I'm just not the type to moan, we just arn't the ones trying to make a movie under a studio that likes to rape franchises.