I guess I'm late but here's a reply...
What you have to understand is that French B-Schools are mostly Grandes Ecoles, you gain access to them after 2 years of extremely intense prep' classe (2 years of sacrificing one's social life, lot's of sweat and tears, high intellectual stimulation, constant belittling from the faculty) so once inside the top B-schools, you have guaranteed yourself a life without unemployment, no need for effort anymore.
So basically academically the courses are Bullsh**, most french students don't even bother going to class (particularly the first year out of 3), but I know for a fact that at EDHEC in Nice (the finance campus) it's not the case, you really have to work... (No clue about how the academic level increases after the first year in other schools)
Yet, I would still pick HEC because it's branding has no equal in France, EDHEC is an excellent school, becoming more and more recognized worldwide with every passing day but the fact remains that HEC provides France with the majority of its elite (CEO's of the CAC40, ministers, the current president etc.).
So don't hesitate and pick HEC, you can't go wrong with that choice.
PS: I am from EDHEC, and in the end I seldom regret not having given myself another year to try and get HEC or assimilated, EDHEC is really great.