Atypical profile, 2.7 GPA, 700 GMAT, 2.5-yrs prestige WE

Hi,

I've been reading this forum for a while and would really like to hear your opinion. I've searched for stories similar to mine but I feel I'm in a somewhat rare position.

My stats:

• I'm a German citizen, ethnically Turkish.
• I was a community college transfer to University of Michigan Ann Arbor
• I majored in Political Science and it took me 6 years (4 @ UMAA, 2 @ CC)
• I graduated with a 2.7 GPA (some F's on my courses)
• I was active in Mock Trial and finished Top 20 nationally
• My GMAT is a 700
• I currently work as a consultant at McKinsey & Company in Germany, with significant international work experience (no other jobs or noteworthy internships)
  
  (I was interviewed only because a German AP was willing to vouch for me and I did very well in the case interviews)

In less than 2 years time I am expected to pursue an MBA degree. Its important for me that I attend a good school. I'm particularly interested in Columbia, INSEAD, London Business School.

I know that I have very good work experience, but my worry is that my very poor undergraduate performance will hold me back. As a student I certainly dealt with adverse circumstances that made my performance worse, but the majority of it was my own immaturity as a student. I prioritized my social life over all else. I've changed tremendously since, there's no other way to be successful in my current job, and I think I could perform very well at top institutions. I just don't know where I'm likely to be admitted.

There are three things I'm really curious about:

1. What schools would I be competitive at? My interests are INSEAD, Columbia, LBS. Do I have a realistic chance here or should I broaden my search? If so, do you have recommendations on other place where I could apply?
2. Should I retake the GMAT?
   
   I took the original GMAT during undergrad with minimal preparation. I've been retesting myself and think I could realistically score 740-750. Is that enough of a bump to make a difference for me?
3. Should I build an alternate transcript?
   
   I'd really like to avoid this option since my job is extremely intense, but if this is the only way I can be admitted to a good program then I would do it.

I really look forward to hearing from you.

Thanks!