I have not had any real problems, and I opt out every time.
I politely but firmly state to the TSA agent that I am unable to raise my arm over my head. I would like to go through the X Ray lane, but if you are not comfortable with that, I want a private search.
Interestingly, many more male TSA agents than female TSA agents agree to let me go through the X Ray lane.
I cannot recall a time when my belongings were not brought with me.
I go through DEN about 4 times a year, same there.