I did a post on this. I was a nervous wreck but wanted to try it. It worked out for me, but I was watching it like a hawk and also had the collateral ratio set really high so I could get out if need be. It did teach me quite a bit about the way Hero will work and how it being backed by bitshares will affect both markets. It was so interesting, but I don't think my nerves could take much margin trading! :)