Thanks for this input! I hadn't heard of most of these sites. I enjoyed hearing your personal preferences in relation to each device. The only thing I will say about the Holy Trainer is that men with bigger balls wont be comfortable in it, there's a small space between the ring and the tube that pinches some guys with a lot of skin right there at the top, but when it fits, it really fits! I have a collection of metal cages from subs that didn't want them anymore due to fit, and I'm glad to hear suggestions through trial and error.