As far as I remember USS Sulaco and Sephora do not have science labs, lot of space in those ships is used for storage rooms for different cargo (ammo, guns, hangars for drop-ships and armoured vehicles) and mechanisms responsible for arming different cannons. On the other side You can remove most of that stuff and turn this class ship in flying hospital like W-Y do with Panta in Alien3.
it's average game, people who wait for a long time and have seen high quality promo-materials have right to be angry. Still this game is not that bad, controls are easy to learn, guns sound like they should, shooting is enjoyable and design is close to alien universe. Playing in co-op was fun.