I'm not a pilot, but I have been dabbling in flight sims for a few years. I'm also not sure if I'm just extremely lucky, but I have yet to... fully crash the MiG-21 despite going through several landings without having touched the training missions. The worst I've had was a busted main gear. The speed of the landing wasn't what shocked me, it's the way it responds to quick pitch inputs. It seems to like to go to a high AoA before really responding if you pull hard, even at landing speeds, so an attempted late correction to a low approach will just slam your gear into the runway. You really really have to plan ahead, which is one of the things I've rarely put much effort into with flight sims.