I have one. Not necessarily a good one but it is one. Just cheap.
I am disappointed. Was sort of hoping to insert for the commute home. The last bit to make it possible to sit doesn't fit in though. Not sure if it's just me but the pictures seem to suggest the last bit should be outside. I wouldn't say I was adept at taking big things but it's not that big, even the last "ring" doesn't look much bigger than the higher ones, or the glass plug I used to have.
However, the impact is that I can't of course wear it while riding the motorbike and being a kinky slut experiencing a good thrusting going down the motorway.
Oh, and I was hoping for more range of movement as well. It's only a couple of centimetres.
As a review goes that's probably not too helpful.