Guess I would prefer to be tied, with lots of ropes and perhaps leather cuffs. I love to tug on my restraints and being unable to move. Plus it leaves more option open for my rapist as to what to do with me, where to grab what to use.
But I can see the appeal of being held down, with all the skin contact and feeling how strong the rapist is.
Could we go for the combo? Hands tied behind the back/up above the head being held down by a strong body as my pussy/ass is used. Oh, yeah.