Up till now I am liking Pyaray Afzal more. I personally feel Farah and Afzal's chemistry is stronger than Aun and Zara but yes Aun Zara has other strong points.
I think both are romcom but the concepts are different. AZ revolves around importance of family and relations and their love and support. PA is more related to how two totally different people fall in love with each other and love is blind sort of thing I guess.