I can answer your questions about ESSEC (I cant about ESADE because i dont really know the school so I would not be able to answer your questions properly).. I am currently a first year student at ESSEC and I can tell you that, concerning reputation, in terms of company recruiting and alumni, ESSEC truly is a top business school worldwide. We have a network of more than 40K alumni all holding top positions in every sector/industry.. ESSEC is also the primary choice of recruiters in France (and, if you think that there are other top top business schools in France, that must mean something).
In your pros you forgot the flexibility that this school offers: you can choose ALL your courses (a part from 8 core courses that will serve you as a basis for the others), a fact that allows you to shape your academic path towards the sector of your preference (in your case marketing).. On top of that you can add tracks, specialised paths that upon completion are featured on your diploma, and chairs, similar to tracks but they usually involve seminars, smaller groups of students, and are company/mission related.. We have chair partnerships with worldwide known companies (LVMH, KPMG, Accenture etc.) which also allows you to access great networking opportunity.
Concerning the professional experience requirement, i will tell you this: to be honest i was skeptical as you are at the beginning, but now i am frankly glad to be attending this school. I have realised how hard it is to get a job and that, to get any job, previous experience is always required, even for a simple internship.. So i am happy to be acquiring this experience while i am still a student and I am convinced that I will have a competitive advantage with respect to other candidates with no or shorter experience than me. Moreover, the whole process (looking for an internship, shaping your application, interviewing and then doing an internship) is an amazing workshop to truly realise what you want to do in your future: i started my master with no precise plan in mind but now just after one year i know the sector i want to work in, i applied accordingly and in two weeks i am starting to work in the domain i am interested in.
So yes, if you have to validate all of the professional experience, your master will last longer than 2 years, but these two years will represent a period of incredible growth for you on one side, as well as a gradual entry in the work environment.
Finally: ESSEC is a really international school. We have a lot of international students (i am one myself) and the backgrounds we have differ both in terms of origin and in terms of academic background, which i believe adds a good component to the already existing diversity.. I believe the percentage of international students is around 30%. There is, as you said, the Singapore campus, but ESSEC also offers exchanges with some of the best schools in the world, 15 double degrees all over the world.. This has as a consequence that ESSEC is indeed famous in the world (especially in Europe of course). Ranking speaking it is ranked 8th worldwide as a master in management so yes, it is definitely a well known school.
I hope i provided some helpful insights and i apologise for the long reply but i feel really lucky to be studying at ESSEC so i am more than happy to share my point of view!
Good luck with your choice and for your future!