Vanessa Never been able to get one,with my belt on...
Different people take different amounts of effort to reach orgasm. If you are the sort of person who does not orgasm from mental stimuli alone or melt to gentle touches quickly, chances are you will be a lot luckier (depending on your definition of luck of course) with the effectiveness of your belt than someone who does, even if they wear a belt of the same design, with the same amount of effort spent on getting it fitted to their body. Heck, there are even women who struggle to orgasm despite never even having seen a chastity belt, much less worn one.
Other factors to chastity belt effectiveness include things like how much mobility restriction you are willing/able to endure (e.g. thigh bands), and your access/willingness to use technical help like high-power massagers.