IESE is a good school, definitely a top 30 lister. In fact FT rates IESE quiet high. To compare the three colleges you mentioned is a bit difficult. I Would not say that from an applicant point of view its difficult to compare B Schools, but you should look at it like
1. Which companies or sectors I wanted my career grow in? Are they rating the B School I want to join so high?
2. Whats the alternate thinking about the college? Global perspective, strength of alumni connections and entrepreneurial education. Potential salary earnings etc. are also important sometimes.
Anyways for the discussions point of view
INSEAD : Spanning two continents and with a major presence on a third, INSEAD is making strides toward its goal of being recognized as the preeminent international MBA. The one-year general management program operates on campuses in France and Singapore and maintains an alliance with the Wharton School. It is an excellent 1year program (huge difference between a 1 year program and a 2 year program. You cannot do a business plan or have a summer internship in a 1 year program; it is a quick dash). The school is HIGHLY focused on consulting (indeed it is famous as the consulting factory). Like all MBA's focused on banking and consulting they are getting hit very hard recruiting wise. The quality of students is enviable, really great people. The alumni base is stronger in INSEAD and it has more a brand name. Strength is Consulting, though people debate a lot over this.
LBS : Most other business schools'international immersion claims pale in comparison to what London Business School (LBS) offers. Incoming students can expect that 80-85 percent of their classmates will hail from countries outside of the UK.Two year programme, 18mths minimum (higher opportunity cost; better for careeer-switching).Fees: USD 75,000 (GBP 45,500 @ GBP1 = USD1.65). Strengths in Finance (though consulting and industries recruitments are gaining ground too).one intake per year; potentially more dedicated career services, counselling and less competition for on-campus recruiting
IESE - A 2 year program. By far the most international b-school. A lot of schools like to recruit local immigrants and then they list them as internationals because they have dual citizenship / residence. In IESE you get 50 real nationalities and you can exchange in over 13 other top MBA programs throughout the world. Furthermore, IESE has just started a New York campus (in case you did not make the cut for exchange at Columbia but still want the NYC life).