My son has only been using the 13mm silhouette infusion set. It hurts really bad and I never knew there are other options. As Medtronic called and asked us to upgrade our pump to the new 723 model, I asked them if they have infusion set with smaller needles. That's when I was introduced to MIO and then I watched a youtube video here http://www.youtube.com/watch?v=WNcaUtZxKJU and know how it works. At 4:45, the kid in the video says it's basically painless. Those of you who have used MIO please share with me your experiences. Painless? Recommendable? If yes, I will be calling to exchange the order which I just refilled and will be delivered today. Thank you.