[quote=Halvtand]
Thank you for the excellent definitions (I have only played a few hours of EW, and haven't made all kinds of troops yet), but I'm afraid that you didn't quite answer my question. To be frank, my fear is that amongst these various kinds of supersoldiers the normal human will stand pretty much useless. From my point of view any task on the battlefield that can be performed by a normal human can be done as well or better by one of the other lads. What I'm looking for is a real reason to choose a normal human, something that is unique to them beyond the ability to go out for drinks and not cause a bloodbath.
[/quote]

Sorry for that, but to be brutally honest the choice of keeping a soldier human is more of a question of ethics than ability. Because it is a volunteer program (Except for the PSI program), it might be normal for a soldier to have reservations about giving up a part of their humanity. But they are not without their charm, they get access to armor that MEC's cannot use, and that would be redundant of Biotics, such as the Ghost armor (which allows you to turn invisible for a time, with a Batman type grappling hook), or the Archangel Armor (which allows you to fly for a limited time).