I love my BD chalk, but would love to try Magic Chalk and do a comparison.
I have been using BD chalk for about a year. A few months ago, I picked up three boxes of Magic Chalk for $11 just to give it a try. I wound up giving away the Magic Chalk. It's a step up from Masters, but a step down from BD, in that the Magic covers better than Masters but not nearly as well as BD. The Magic is also messier than BD, though not quite as messy as Masters. I will be staying with BD.