I had no problem with the CGI in the movie, it was good, but seeing all those great animatronics and suits really makes my heart bleed they didnt include them, i can't recall a single practical Alien in the movie, and that's a shame.
And to be honest, i think the "we made the suits just for reference" statement from Ridley is pure bullshit, you don't spend a huge chunk of money for those really good and complex suits and animatronics with the intention to erase it all over with CGI, i think Ridley pulled a "thing" here, where they wanted to go practical and decided during post production to make everything CG instead.
Unlike most people on here i actually like CGI in movies, i really do, but it would have been ten times more creepy if there was a guy slowly walking around on the dust filled spaceship instead of the hyperactive AvP-version we got instead.
The design is awesome, this is the closest to the original big-chap design by far.