That's a bit naive. Even if I had never worked for an ex McK partner at a B4, bid against McK, worked besides McK, had an ex McK as direct client and attended an MBB target MBA (clue, I have) I would be able to tell you (as could any reasonably competent graduate) that, in general, there is little discernible difference in intellectual ability, thought process and output of your average MBBer and the average non-audit/technie big 4 consultant. Partially, that's due to the fact that no client is exactly trying to split the atom - most business problems are complex but unoriginal conundrums, usually based on crap data, and more than often solvable in different ways. So comparing solutions and how consultancies go about them is most effectively done by measuring the outcome, which to my knowledge they tend to deliver. Another part of it is that (surprise) they are just people - with their own pressures, issues and motivations. Sure they are all hired from top schools and work for a firm with outsize reputation and fees to match, but to somehow expect them and McK to be consistently above the rest is plain unrealistic and to a large degree the product of envy and/or inexperience.