Pros: You get more readers/emails. Works best for those unafraid of working directly with readers (not scared to poke at them if they haven't reviewed).
Cons: Less desirable for those shy to poke at unresponsive readers.
Pros: All R&R perks, plus AXP will poke at readers not responding. More motivated reviewers.
Cons: Costs a little more, fewer reader contacts provided.