I used to spin the tomahawk while training students.
The first one I did was solo at 6000ft near Perth and all happened very quickly.
After that with the students everything slows down because you know whats happening (and you make damn sure you only have 0.25 tanks full). More fuel = higher rotation rate in the tommy
Now I can patter all the way through the spin, take it from vertical to flat spin and back again. Its more the shock and srange sensations I think make you feel ill.
Personally I don't mind spinning but I don't get a great thrill out of doing it so unless requested by a student I don't do them.
Although on the 4 th lesson of the day doing steep turns my body does sometimes start rebeling if I havn't eaten something for lunch.
I actaully had a chat with my AME about spinning last medical. He was asking about what technique I used to recover. Then started going through one of the "standard techniques". I hopefully now have convinced him to read the POH and do what it tells you to do. Not some standard thing which has been talked about in the club bar.
MJ