They won't be looking for techies anyway. the main difficulties in crossing from SI into 'advisory' are around culture and quality assurance. You need to show them that you can not only lead the SI piece itself, but also understand how this enables enterprise level change end to end - tie it back into whatver functions will be affected by the integration, and discuss the bigger picture. That essentially is what advisory is - look at the macro level, boil down into specifics, then tie the whole thing back into a (hopefully improved) macro level. On the cultural side the biggest hurdle is usually having the right level of 'polish' - generally the top end SI firms, like ACN, Cap, IBM, will be trusted to have this, while others - the pre-packed ones like Cognizant etc - will not be implicitly trusted to impart this polish so you'll need to work that little bit harder to impress. Also teams will be smaller, and more emphasis (much more in fact) placed on leadership not in the project leading sense, but in the more vague qualities of leadership/charisma to inspire stakeholders/potential captain of industry type leadership.
