It has not been easy to reconcile contemporary class-action practice with traditional adversary procedure. For that matter, it is not easy to craft a unitary "class-action" procedure that serves well the many different purposes pursued by the many different species of class actions. The practice has flourished, but few would dare say it has really matured. Many problems remain.
Cooper, Edward H. "Rewriting Shutts for Fun, Not to Profit." UMKC L. Rev. 74, no. 3 (2006): 569-83.