It doesn't matter which you're studying because both are accepted by universities.
Course load: I agree that Cambridge has a greater course load and is more rigorous than Edexcel, BUT that existed till last year. This year all Edexcel specifications have been amended drastically (except for Mathematics) and the topics and testing procedures have become tougher and more complex, even tougher than Cambridge (You can dig the evidence if you compare syllabuses of both)
Recognition: Cambridge is more attractive to students due to the famous 'Brilliance Award'. High achieving students are honored through this system which unfortunately Edexcel doesn't provide.
Both have introduced the new A* system to distinguish 'true' students.
I think the biggest drawback of Edexcel is that it discloses all the marks to students which might create certain form of inferiority in certain students but also encourages students into competition (on the plus side) which might bring better results in the long run. Cambridge has a better system of working, everything is organized, there's teacher trainings, evaluations and yearly syllabus refinement and great choice which Edexcel lacks of. But I love Edexcel's BTEC and other programs plus the recently posed ResultsPlus. I actually used ResultsPlus and it was astounding!
