I spent three years on the London management team of large global consultant firm. Each year the London practice recruited about 10 MBA’s from Insead, Harvard, MIT, Wharton, IE, IMD, Judge, Yale, Kellogg, etc. I would advise the following:It is pretty pointless arguing which individual school is the best. It has been Harvard, it has been Kellogg, INSEAD has been as high as second in the world and then down again. There are consistent Top Ten schools and they are all worth the money when you are willing to treat the expense as a professional investment. Type “Global MBA Top Ten” into google and you’ll get the idea of who they are.Below these Global Top Ten, each country has a “national” top division – in the UK it would include Manchester, Warwick, Strathclyde, etc. These are in the Global Top 50/75 List. Sometimes one of these schools will jump into the Global Top Ten, but it is a rare occurrence and usually a one-off.Within niches some Top 50 B-school punch above their weight – Warwick for a while had an extra value if you were focussing on a city quants post for example, because they had a good maths module. Strathclyde has been the best BUSINESS school in Scotland for thirty years, but outside of Scotland many firms think it is an ex-Poly and assume that Edinburgh or Glasgow Uni’s would be a better source for MBA’s (they’re not!). This level of local knowledge is only important if you’re applying to a Top 50 school. Top 10, it’s not an issue.However, the brand of the B-School is not the only thing to consider. The 1 or 2 years spent on an MBA will be one of the most intense and life-changing experiences you are ever likely to enjoy. Much of that will be wrapped up in the cultural aspect of the program and this is very much a question of personal choice. Do you want to spend two years in leafy Cambridge, Mass. along with mainly white, well heeled Ivy League-ers? Or do you want to mix it with thirty different races at INSEAD? Or would you prefer the more hands-on learning that many feel can be found at Ashridge? Or would a Top Ten school simply be too full of over-competitive snobs?As to whether the MBA investment is worth while, that depends very much upon the individual. Not even the best MBA will make a dullard a star, and as the MBA industry expands an increasing number of dullards are willing to spend 50K of their own money on try to polish themselves out of looking like a turd. Whenever I hired an MBA I always made sure the first projects were hard, hard work – the type that knocks that polish off to see what’s underneath. What has not changed is that if you are the real-deal in terms of raw material, then coming in the top 5 of your class at a top MBA WILL catapult you into the career stratosphere in a way that very few other things will.