I've heard that Retro has an 80% success rate whereas MC has a 20% - I'm not saying that's true, it's just what I read online. If you can afford it, I would say it's worth a shot, but don't get your hopes up about it... go with an open mind.
I've never been but I've read a lot of stories about it and the dialoging online. I wouldn't have tried so hard to go if I didn't think it would matter to me.
