About the heights, someone said Steele was 6'7, so I suppose with the added height of the suits, he and the others (the group of three all look the same height to me) are about 6'11? They are standing further away than Rodriguez in that photo so maybe they look smaller than they should. Still, I would prefer if they were all half a head taller than that if I'm right about the heights.
Generally, I like the feel given off by these photos, kind of reminiscent of the first film. Even Brody looks pretty solid. The classic Pred looks good, although I dunno if they got his teeth right, can't tell properly. I am also relieved we don't have that plastic fat look from AVP. The one on the right should be slimmed down a bit having said that.
Overall, fairly relieved, but they should have used genuine 7ft+ actors for the creatures.