Should I consider leaving Delhi University for B. R. Ambedkar University, Delhi?

It depends on the college you are getting admission under Delhi University. If you are able to get into one of the top colleges in the North or South campus of Delhi University, you should stick with it. Otherwise, choosing AUD over DU will be better. One other thing that you should consider while making the choice is your ultimate goal, i.e. research/job. You should definitely choose AUD if you are interested in pursuing research.