I've never grown in anything but Miracle Grow, or at least had a large amount of MG in my mix. I'm not a very experienced grower though. I've seen a few harvests in the past, but this is my first grow in about 8 years. I went with MG this time because it's what I used back then. I don't really ever remember having any major soil problems. It burns seedlings a little... but so does Fox Farms. I've seen just as many burned plants that were being grown in "perfect" soil and fed with hundreds of dollars worth of nutrients. I think part of the bad reputation comes from the fact that the type of people who use MG are also usually the type of people who have crap lights, temp and ventilation issues, and bad growing habits.
That said, Miracle Grow won't be getting anywhere near my next grow. I'm going all organic. I want to see the difference first hand.