Well! I received my MGX last week and yesterday evening was the first chance I had to try it out.
I was a bit apprehensive about inserting it into my anus as I imagined it was going to be a bit painful. I carfully washed my passage and used a finger to lube it with KY Jelly and then spread vaseline along the length of the MGX and I am pleased to say it slipped in without a problem and I was amazed how it was suddenly sucked up there once past a certain point. It felt comfortable from the start but I relaxed for about 10 minutes befor trying contractions. Over the course of the time I had it in I felt a few slight body spasms but nothing outstanding and most of the time it felt like I needed to pee when I contracted.
I tried out various positions but the one that felt like it was making most contact with my prostate was the one suggested on the packaging, i.e. on my side with bottom leg straight out and top leg at a 90 degree angle, so I mainly kept to that.
I hope to get in about 2-3 sessions per week, so I will keep my progress posted when it occurs.