Which is Better????

i have a question to ask... Is it better to work in a Big 4 which gives a great deal of exposure,but they let us specialize in one specific area right from Articleship period...or a firm next to big 4 which gives its article assistant experience in all fields...thereby giving us a holistic learning platform... What do you Suggest Sir??? Because at such initial Phase..when we start our Career in CA we are hardly aware about our Interest in any specific area...