1. Current simulator modeling DOES NOT give an accurate replication of jet airliner stalls, especially at high altitude. Both Airbus and Boeing say stalls in the a/c are more violent. They've recently agreed to a simulation model that works for n/b a/c (but not w/b's) that we might get to experience in a couple years.
2. You'll rarely see more than 5, or perhaps 6, degrees NU in an airliner above FL300. You need a v/s of greater than 2000-2,800 FPM to see pitch attitudes that exceed 5-6 degrees NU.