Yes I tried moxi recently.
My son was in a breech position and I was willing to try anything! I was actually under consultant care for diabetes and he was the one who mentioned it to me as I didn't even know anything like that existed!
I had a thread in here asking for advice as well. Anyway, my son didn't change position. I opted for an ECV to have him turned but unfortunately it wasn't recommended on the day as the cord was seen around his neck whilst I was being prepped for the EVC.
In fact, I also had reduced movements for two days prior to that. My son was moving but not as much. I was sent to triage and I was kept in the same night and my son was delivered by emergency c section early next morning. I was in complete shock to say the least!
However, he's doing very well. As well as a 15 days old can do 
I cannot say if the moxi contributed to the cord being around his neck or not. I remember reading that there's a risk of this happening with moxi as it makes babies moves too quickly etc.
It didn't work for me unfortunately.
I feel extremely lucky to have my son with me as I dread to think what could have happened. In hindsight, I wouldn't do the moxi and would opt for a CS as it's safer for both mum and baby. I would also not have an ECV but that's just my personal choice based on research I have done after my experience.
Good luck in whatever you decide and I hope you make an informed choice 