It really depends on: what business will you be doing, and who will you be doing business with?

Personally, in my carreer - I work alongside some of the most brilliant executives & business owners in Canada. My experience leads me to believe that a formal education gives you very well-rounded start in most areas of business alongside more depth of understanding. It does well to answer the question of "where do I start & what do I need to know?"

In entrepreneurship, information is leverage, and leverage is key. So, if you see yourself in a vertical where the sort of information offered in most traditional business schools will be of benefit, and you have the financial ability to commit to going back to school for this program - I don't see why not.

At the same time, building experience ontop of that information or education is where you will really shine. If "the price is right" for you, and you don't see a viable alternative - do it. But it's most definitely not the only option.