I'm no expert either, but I've read a few things here and there. I did read a cool article in Maxim several years ago where they broke down the Navy Seals, Delta Force, Spetsnaz, GIGN, GSG9, SAS. They did some back ground, training, had a former member recount a story, and also did like a historical highlight.
A guy here at work used to be stationed at Ft. Bragg when he was in the army. Also stationed at Bragg are the Rangers and Delta. So frequently, the regular GI's were tabbed as "bad guys" to help train Spec. Ops. in various scenarios. Needless to say, the Spec. Ops units train much differently and play by a different set of rules. When the GI's got their asses beat, they literally got their asses beat.