I was looking at an anatomical program and it seems to be quite shallow, it seems like the head of most toys would miss this and press on the bladder instead unless you had good movement and the toy moved back and forth a lot to move out enough to hit it with the head.
That’s what I’ve been saying all along. The prostate is normally located very close to the internal sphincter. That’s why when using the Njoy, for instance, you shouldn’t go to deep. As far as other toys, like my Prosgasm, for instance, it’s not necessarily the head of the toy that’s hitting your prostate but the girthiest part of the toy which is not too far from the base.