This paper evaluates the performance of two seminal rateless erasure codes, LT Codes and Online Codes. Their properties make them appropriate for coping with communication channels having an unbounded loss rate. They are therefore very well suited to peer-to-peer systems. This evaluation targets two goals. First, it compares the performance of both codes in different adversarial environments and in different application contexts. Second, it helps understanding how the parameters driving the behavior of the coding impact its complexity. To the best of our knowledge, this is the first comprehensive study facilitating application designers in setting the optimal values for the coding parameters to best fit their P2P context.