this cannot be adequately covered in the simulator however sophisticated. This is because there are no physiological effects such as 'g' forces
The vital skill in unusual attitude recovery training is the recognition of the situation by simply looking at the flight instruments. If the aircraft is at 135 degrees angle of bank and 30 degrees nose high attitude then if the pilot has been properly trained he will know that certain actions are necessary to get right side up. This is easily taught in most airline type simulators. Certainly in the 737 simulator I use, the instruments will also show a complete barrel roll although of course the simulator doesn't move.
While it would be nice (?) to have a simulator that gives you a gut wrenching vomit inducing 3G manoeuvre, it isn't going to happen. If you know how to recover from aforesaid manoeuvre in IMC by observing the flight instruments and correcting via the flight instruments then that is better than just reading it from a book. To say that it is dangerous to teach unusual attitude recovery training simply because the G forces can not be replicated, is nothing more than negligence - leaving the student or whoever, right out on a limb and the unfortunate passengers too. It is similar to saying it is too dangerous to teach you how to swim but I'll teach you how not to go near the water..